Carminative Tea (Loose Herbs) by Gaia Garden Herbals Inc.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Asthma. Oral anise has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with allergic asthma shows that drinking one cup of tea prepared with multiple ingredients, including anise, twice daily for 6 months reduces sleep discomfort, cough frequency, and cough intensity when compared with placebo (19056). It is unclear if these findings are due to anise, other ingredients, or the combination.
• Constipation. Oral anise has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small crossover trial in patients with constipation shows that taking an herbal tea containing a combination of anise, fennel, elderberry, and senna daily for 5 days can decrease colon transit time, increase the number of daily evacuations, and improve the perception of bowel function when compared with placebo (49494). It is unclear if these findings are due to anise, other ingredients, or the combination.
• Depression. It is unclear if oral anise oil is beneficial in patients with depression. Details: A small clinical study in adults with mild to moderate depression and irritable bowel syndrome (IBS) shows that taking enteric-coated anise oil 200 mg three times daily for 4 weeks improves symptoms of depression by an additional 28% when compared with placebo and an additional 32% when compared with peppermint (94947).
• Diabetes. It is unclear if oral anise seed powder is beneficial in patients with diabetes. Details: A small clinical study in adults with type 2 diabetes shows that taking anise seed powder 5 grams daily for 60 days decreases fasting blood glucose levels by 36%, total cholesterol levels by 7.5%, and triglyceride levels by 15% when compared to baseline. Fasting blood glucose significantly increased in the control group, and total cholesterol and triglyceride levels were relatively unchanged (94953).
• Dysmenorrhea. Although there has been interest in using oral anise for dysmenorrhea, there is insufficient reliable information about the clinical effects of anise for this purpose.
• Dyspepsia. It is unclear if oral anise powder is beneficial in patients with dyspepsia. Details: A small clinical study in adults with postprandial distress syndrome shows that taking anise powder 3 grams three times daily for 4 weeks improves quality of life and symptoms of functional dyspepsia when compared with placebo. Of the evaluated symptoms, improvement was seen in all categories when compared to placebo except for nausea and vomiting, which were present in less than 5% of patients at baseline (94944,94945).
• Irritable bowel syndrome (IBS). It is unclear if oral anise oil is beneficial inpatients with IBS. Details: A small clinical study in adults with IBS shows that taking enteric-coated anise oil 200 mg three times daily for 4 weeks eliminates IBS symptoms in 75% of patients, compared with 53% of patients taking peppermint oil and 35% taking placebo. The greatest symptom improvement occurred with abdominal pain, bloating, and reflux, and was maintained for an additional 2 weeks after treatment completion (94946).
• Lactation. It is unclear if oral anise tea is beneficial for increasing human milk production. Details: A moderate-sized clinical study in post-partum adults shows that drinking a tea containing anise 2 grams and black tea 1 gram 3 times daily with meals for 7 days increases the volume of pumped human milk on day 7 by an average of 98 mL and 113 mL, respectively, when compared with a placebo of black tea 3 grams daily and when compared with a control group not assigned to any tea or galactagogues (112863).
• Lice. Topical anise has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children 6-14 years of age shows that application of a topical spray containing anise oil, coconut oil, and ylang ylang oil three times at 5-day intervals is 92% effective for the treatment of head lice and seems to be comparable in effectiveness to a spray containing permethrin, malathion, piperonyl butoxide, and isododecane (13483).
• Menopausal symptoms. It is unclear if oral anise seed extract is beneficial in patients with menopausal symptoms. Details: A small clinical study in postmenopausal adults shows that taking anise seed extract 330 mg three times daily for 4 weeks reduces the frequency and severity of hot flashes by approximately 75% when compared with placebo (94948).
• Migraine headache. It is unclear if topical anise essential oil is beneficial in patients with migraine headache. Details: A small clinical study in adults with migraine headache shows that applying 2 mL of a cream containing anise essential oil 7% to the temporal and forehead zones at the onset of a migraine reduces the impact of the headache by approximately 10% when compared with a control cream. However, there was no effect of the anise cream on analgesic use or average headache severity when compared with placebo cream. Additionally, due to the strong smell of the anise cream, patient blinding may have been compromised (100166).
• Premenstrual syndrome (PMS). It is unclear if oral anise extract is beneficial in patients with PMS. Details: A small clinical study in female college students with PMS shows that taking anise extract 110 mg three times daily, starting 7 days before menstruation and ending 3 days after, improves concentration, mood, irritability, sleep, food cravings, and other symptoms of PMS, as measured using the Premenstrual Symptoms Screening Tool, when compared with placebo (103875). More evidence is needed to rate anise for these uses.

(Read more about ANISE)

POSSIBLY INEFFECTIVE

• Diabetes. Most research shows that oral Ceylon cinnamon does not benefit patients with type 2 diabetes. Details: Clinical research in adults with well-controlled type 2 diabetes shows that taking Ceylon cinnamon 1-9 grams orally daily for 2-3 months does not improve fasting blood glucose when compared with placebo or a control group (99436,99437,99439). However, one small clinical study in adults with poorly controlled type 2 diabetes despite treatment with metformin showed a trend toward improvement in fasting blood glucose. Taking Ceylon cinnamon 3 grams daily for 8 weeks reduced fasting blood glucose by 12 mg/dL, compared with an increase of 9 mg/dL in those taking placebo. Although this difference was not statistically significant, the study might not have been adequately powered to show a difference. Also, the 8-week duration of this study was too short to reliably assess the effect of Ceylon cinnamon on glycated hemoglobin (HbA1c) (99438). Conversely, a large study clinical study in patients with type 2 diabetes conducted in India shows that taking Ceylon cinnamon 1.5 grams daily for 4 months improves fasting blood glucose by 40 mg/dL and HbA1c by 1% when compared with placebo but does not significantly improve either outcome when compared to baseline (112422). However, it is unclear whether modifications to diabetes medications were allowed during the study.
• Obesity. Preliminary clinical research suggests that oral Ceylon cinnamon does not help with weight loss. Details: Preliminary clinical research shows that drinking black tea steeped with 3 grams of Ceylon cinnamon dried powder three times daily for 8 weeks does not affect weight, waist circumference, or blood pressure when compared with baseline or black tea alone in overweight patients with diabetes (95597). Other preliminary research shows that taking Ceylon cinnamon, titrated up from 85 mg to 500 mg, daily for 3 months has no effect on weight or body mass index, but may reduce hip circumference by 1.8 cm, when compared with baseline in healthy, mostly normal weight adults (97250).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). A nasal spray containing a Ceylon cinnamon extract might improve symptoms of allergic rhinitis. It is unclear if oral Ceylon cinnamon is beneficial. Details: Using a nasal spray containing a polyphenol-rich standardized extract of Ceylon cinnamon 1 mg/mL, twice daily in each nostril for 7 days, reduces the severity of nasal, eye, and nocturnal symptoms, and improves quality of life and work productivity when compared with placebo in people with seasonal allergic rhinitis who are not using any other medications for the condition (103169). One small clinical study in patients with seasonal allergic rhinitis shows that taking a specific combination product (ClearGuard, Access Business Group LLC) containing Ceylon cinnamon extract, acerola fruit concentrate, and powdered Spanish needles (Bidens pilosa) orally, 450 mg three times daily for 3 days, improves nasal symptoms 8 hours after, but not immediately following, a nasal allergen challenge when compared with placebo (23709).
• Chronic obstructive pulmonary disease (COPD). Ceylon cinnamon has only been studied in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in adults with COPD shows that taking a combination product containing extracts of Ceylon cinnamon, ginger, alpinia, cardamom, and saffron in honey 3 times daily for 8 weeks improves confidence in leaving home and the ratio of forced exploratory volume per second to forced vital capacity of the lungs (FEV1/FVC) when compared with placebo. However, the combination product does not improve most measures of respiratory function or symptoms such as cough, phlegm, chest tightness, dyspnea, reduced energy levels, sleeping disorders, or activity limitations when compared with placebo (111542). It is unclear if these effects are due to Ceylon cinnamon, other ingredients, or the combination.
• Common cold. Although there has been interest in using oral Ceylon cinnamon for the common cold, there is insufficient reliable information about the clinical effects of Ceylon cinnamon for this purpose.
• Denture stomatitis. It is unclear if topical Ceylon cinnamon is beneficial in patients with denture stomatitis. Details: A small clinical trial in patients with denture stomatitis shows that using 10 mL of a mouthwash, as well as a denture spray, containing Ceylon cinnamon essential oil three times daily for 15 days modestly reduces Candida measurements and improves the severity of stomatitis in the oral mucosa and dentures when compared with baseline (108262). The validity of these findings is limited by the lack of a comparator group.
• Diarrhea. Although there has been interest in using oral Ceylon cinnamon for diarrhea, there is insufficient reliable information about the clinical effects of Ceylon cinnamon for this purpose.
• Dysmenorrhea. It is unclear if oral Ceylon cinnamon is beneficial in patients with dysmenorrhea. Details: One preliminary clinical trial in adults with primary dysmenorrhea shows that taking Ceylon cinnamon orally 1 gram three times daily during the first 72 hours of menstruation over the course of two cycles decreases pain by 1.6 points on a 10-point visual analog scale when compared with placebo (99875). The use of a per-protocol analysis limits the validity of these results.
• Dyspepsia. It is unclear if oral Ceylon cinnamon is beneficial in patients with dyspepsia. Details: A small clinical trial in patients with functional dyspepsia shows that taking one capsule of Ceylon cinnamon oil, providing an unspecified dose, three times daily for 6 weeks does not improve symptoms of dyspepsia when compared with sesame oil as placebo (108263).
• Hypertension. It is unclear if oral Ceylon cinnamon is beneficial in patients with prehypertension. Details: A small clinical trial in patients with prehypertension shows that taking Ceylon cinnamon 500 mg three times daily for 90 days does not affect final blood pressure measurements when compared with placebo. However, there was a modest reduction in mean daytime systolic blood pressure when compared with placebo (108261).
• Impaired glucose tolerance (prediabetes). Although there has been interest in using oral Ceylon cinnamon for impaired glucose tolerance, there is insufficient reliable information about the clinical effects of Ceylon cinnamon for this purpose.
• Influenza. Although there has been interest in using oral Ceylon cinnamon for influenza, there is insufficient reliable information about the clinical effects of Ceylon cinnamon for this purpose.
• Intestinal parasite infection. Although there has been interest in using oral Ceylon cinnamon for intestinal parasite infection, there is insufficient reliable information about the clinical effects of Ceylon cinnamon for this purpose.
• Irritable bowel syndrome (IBS). Oral Ceylon cinnamon has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination of powdered Ceylon cinnamon 1.5 grams, dried bilberry fruit 10 grams, slippery elm bark 4.5 grams, and agrimony 3 grams orally twice daily for 3 weeks increases the number of bowel movements and reduces symptoms such as abdominal pain, bloating, flatulence, and straining in patients with diarrhea-predominant IBS (35462).
• Migraine headache. It is unclear if oral Ceylon cinnamon is beneficial in patients with migraine headache. Details: Preliminary clinical research shows that taking Ceylon cinnamon powder orally 600 mg three times daily for 2 months, in addition to regular medications for migraine, decreases the frequency, severity, and duration of migraine attacks when compared with placebo (104520).
• Polycystic ovary syndrome (PCOS). It is unclear if oral Ceylon cinnamon is beneficial in patients with PCOS. Details: Taking Ceylon cinnamon orally 1.5 grams daily for 3 months in adults with PCOS does not appear to improve fasting insulin levels, fasting glucose levels, glycated hemoglobin, testosterone, lipid parameters, body weight, or body mass index when compared with placebo (97248). However, a meta-analysis of 5 low-quality studies shows that taking Ceylon cinnamon 0.5-1.5 grams daily for 8 weeks to 1 year reduces insulin resistance and fasting serum insulin levels (104518). Ceylon cinnamon has also been evaluated in combination with other ingredients. Some preliminary clinical research in overweight adults with PCOS shows that taking three tablets of a combination product containing extracts of Ceylon cinnamon, licorice root, peony root, and St. John's wort, providing the equivalent of 750 mg of dried herb for each ingredient, daily for 3 months, plus tribulus extract for 10 days during the follicular phase, in conjunction with lifestyle modification reduces the time between periods by around 43 days when compared with lifestyle modification alone. The rate of conception was four times higher with this combination when compared with control (97216). Another small clinical study shows that taking a mixture of Ceylon cinnamon, spearmint, ginger, and sweet orange daily for 3 months, in addition to clomiphene citrate for 5 days of each menstrual cycle, improves serum antioxidant levels, fasting blood glucose, and serum insulin levels when compared with clomiphene citrate alone. It is unclear whether these changes are associated with an increase in ovulation and pregnancy rates (103168). In both studies, it is unclear if the effects are related to Ceylon cinnamon, other ingredients, or to the combinations used.
• Premature ejaculation. Topical Ceylon cinnamon has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In patients with premature ejaculation, applying a multi-ingredient cream (SS Cream) containing Panax ginseng root, Angelica root, Cistanches deserticola, Zanthoxyl species, Torlidis seed, clove flower, Asiasari root, Ceylon cinnamon, and toad venom to the glans penis one hour prior to intercourse and washing off immediately before intercourse improves ejaculatory latency when compared with placebo (2537). The effects of Ceylon cinnamon alone are unclear. More evidence is needed to rate Ceylon cinnamon for these uses.

(Read more about CEYLON CINNAMON)

POSSIBLY EFFECTIVE

• Dysmenorrhea. Taking fennel oil or extract by mouth may reduce pain in patients with primary dysmenorrhea. This benefit may be similar to ibuprofen or mefenamic acid. Details: Two separate meta-analyses in patients with primary dysmenorrhea show that taking fennel oil or fennel extract for 1-6 menstrual cycles reduces dysmenorrhea pain when compared with placebo. Improvement in pain was similar when compared with ibuprofen or mefenamic acid. In the included studies, doses of fennel oil ranged from 3-30 drops every 4-8 hours, and doses of fennel extract ranged from 30-230 mg daily (104196,108972). However, most studies included in these meta-analyses were small and low-quality, and all studies were conducted in Iran. Higher quality studies in other geographic locations are needed to confirm these findings.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. Although there has been interest in using oral fennel for anxiety, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Bronchitis. Although there has been interest in using oral fennel for bronchitis, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Cancer. Although there has been interest in using oral fennel for cancer prevention, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Cholera. Although there has been interest in using oral fennel for cholera, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Colic. Small clinical studies suggest that oral fennel may reduce crying time in infants with colic. However, most research to date has evaluated fennel in combination with other ingredients. Details: A meta-analysis of three small clinical studies shows that giving fennel to infants with colic can reduce crying time by about 72 minutes daily when compared with placebo (97497). However, the studies included in this meta-analysis were at medium to high risk of bias, and the placebo response rate was high in all of the included studies. Additionally, two of the three studies evaluated combination products (16735,19715,49428). In the one study that used fennel alone, administering 5-20 mL of fennel seed oil 0.1% emulsion daily for one week led to colic relief in 65% of infants, compared with 24% of infants receiving placebo (49428). The other studies evaluated fennel in combination with lemon balm and German chamomile (ColiMil) or in combination with chamomile, vervain, licorice, and lemon balm (Calma-Bebi, Bonomelli). These combination products produced a response in 57% to 85% of infants, compared with 26% to 49% of infants receiving placebo (16735,19715).
• Constipation. Oral fennel has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small crossover trial in patients with constipation shows that drinking an herbal tea containing 3 grams of a combination of fennel, anise, elderberry, and senna daily for 5 days can decrease colonic transit time, increase the number of daily evacuations, and improve the perception of bowel function when compared with placebo (49494). Another small clinical study in elderly patients with constipation shows that drinking a specific tea (Smooth Move, Traditional Medicinals) containing fennel, senna, licorice, orange peel, cassia cinnamon, coriander, and ginger for 28 days can increase the number of bowel movements when compared to baseline (46196). The validity of this finding is limited by the lack of a comparator group. Additionally, a small clinical study in patients aged 60-65 years with functional constipation shows that taking a traditional Iranian combination product containing 5 grams each of fennel seed and rose flower, dissolved in water twice daily before meals for 4 weeks, improves constipation severity and stool consistency when compared with polyethylene glycol 10 grams. Improvements in constipation severity persisted in both groups 4 weeks after treatment completion (108973). However, polyethylene glycol is usually taken at a higher dose of 17 grams daily, limiting the validity of these findings.
• Cough. Although there has been interest in using oral fennel for cough, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Dementia. Although there has been interest in using oral fennel for dementia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Diabetes. Although there has been interest in using oral fennel for diabetes, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Dyspepsia. Although there has been interest in using oral fennel for dyspepsia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Flatulence. Although there has been interest in using oral fennel for flatulence, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Hirsutism. It is unclear if topical fennel is beneficial in patients with hirsutism. Details: A small clinical study in females with male pattern body hair due to unknown causes shows that applying a fennel 2% cream twice daily for 12 weeks can reduce hair diameter by approximately 19% when compared with placebo (49429).
• Insomnia. Although there has been interest in using oral fennel for insomnia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Irritable bowel syndrome (IBS). Oral fennel has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in adults with either diarrhea- or constipation-predominant IBS shows that taking two capsules containing fennel essential oil 25 mg and curcumin 42 mg per capsule (CU-FEO, Alfa Wassermann S.p.A.) twice daily for 30 days improves overall ratings of abdominal pain, abdominal distention, and quality of life by 24% when compared with placebo (97422).
• Lactation. Although there has been interest in using oral fennel to stimulate breastmilk production, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Menopausal symptoms. Small clinical studies suggest that oral fennel oil or fennel seed powder may modestly improve menopausal symptoms. Details: One small clinical trial in adults with medium severity menopausal symptoms shows that taking fennel essential oil 60 mg daily for 8 weeks improves scores on the Menopause Rating Scale when compared with a sunflower oil placebo (97498). Another small clinical study in postmenopausal adults shows that taking fennel seed powder 2 grams daily for 8 weeks improves scores on the Kupperman Menopausal Index when compared with placebo (104198). Fennel has also been evaluated in combination with other ingredients. One small clinical study shows that taking a combination of fennel 120 mg, chamomile 1000 mg, and saffron 60 mg daily for 12 weeks reduces physical, psychological, and urogenital symptom scores on the Menopause Rating Scale when compared with placebo or lower doses of the combination (103628). Additionally, a moderate-sized clinical study in postmenopausal women conducted in Iran shows that taking combined fennel and valerian extract 500 mg twice daily for 8 weeks modestly improves self-reported scores for frequency and severity of hot flashes but does not improve sleep quality or duration of hot flashes when compared with placebo (112369). However, it is unclear if these benefits are due to fennel, other ingredients, or the combination.
• Nausea and vomiting. Although there has been interest in using oral fennel for nausea and vomiting, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Nocturnal enuresis. Although there has been interest in using oral fennel for nocturnal enuresis, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Osteoarthritis. It is unclear if oral fennel extract is beneficial in patients with knee osteoarthritis. Details: A small clinical trial in females with osteoarthritis of the knee shows that taking powdered fennel extract 800 mg daily for 2 weeks reduces pain and disability scores, but not stiffness, when compared with placebo (104199).
• Polycystic ovary syndrome (PCOS). It is unclear if oral fennel is beneficial in patients with PCOS. Details: A small clinical study in patients with PCOS shows that taking two fennel capsules, containing anethole 21-27 mg per capsule, daily along with a hypocaloric standard diet or a hypocaloric high-protein diet for 3 months does not reduce body weight or improve androgenic parameters such as testosterone levels, sex hormone-binding globulin levels, or free androgen index, when compared with these diets plus placebo (104197). Fennel has also been evaluated in combination with other ingredients. A clinical study in patients with oligomenorrhea due to PCOS shows that taking a traditional combination product (Aslagh) containing equivalent amounts of essential oils of fennel, wild carrot seeds, and Vitex agnus-castus fruit for 3 months, either alone or in combination with metformin, improves rates of menstrual bleeding and menstrual cyclicity similarly to metformin alone. All three groups experienced a significant improvement from baseline. Aslagh was taken as two, 500-mg capsules twice daily, except during menses; metformin was titrated over one week to a dose of 500 mg three times daily (108974). Additionally, a moderate-sized clinical study in patients with PCOS shows that taking fennel 60 mg and Elwendia persica 25 mg twice daily for 4 months modestly improves number of ovarian follicles and body mass index when compared with placebo; however, when compared to baseline, the combination also improves hirsutism scores and menstrual cycle duration and interval (112370). It is unclear if these effects are due to fennel, other ingredients, or the combination.
• Rheumatoid arthritis (RA). Although there has been interest in using oral fennel for RA, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Sexual desire. It is unclear if oral fennel is beneficial for improving sexual desire. Details: A small clinical study in postmenopausal adults shows that taking fennel seed powder 2 grams daily for 8 weeks does not improve scores on the Hurlbert Index of Sexual Desire when compared with placebo (104198).
• Sunburn. It is unclear if topical fennel emulsion is beneficial for preventing sunburn. Details: A small clinical study shows that applying a fennel 5% emulsion topically prior to ultraviolet (UV) exposure can reduce sunburn by 65% when compared with a control (49518).
• Upper respiratory tract infection (URTI). Although there has been interest in using oral fennel for upper respiratory tract infections, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Vaginal atrophy. It is unclear if intravaginal application of fennel cream is beneficial in patients with vaginal atrophy. Details: A small clinical study in postmenopausal adults shows that applying 5 grams of a fennel 5% cream to the vagina once daily for 8 weeks seems to reverse vaginal thinning, improve vaginal pH, and reduce symptoms of vaginal atrophy such as itching, dryness, and pain with intercourse when compared with placebo (92509). Patients in the fennel group also rated their sexual function to be improved when compared with those receiving placebo (97496). More evidence is needed to rate fennel for these uses.

(Read more about FENNEL)

POSSIBLY EFFECTIVE

• Anxiety. Orally, a specific lavender oil product (Silexan) seems to improve anxiety in some patients. Lavender oil aromatherapy and aromatherapy massage also seem to improve chronic and situational anxiety in some patients. Details: Most meta-analyses and clinical trials in patients with mild to severe anxiety show that taking capsules containing a specific lavender oil ingredient (Silexan, Dr Willmar Schwabe GmbH & Co. KG) 80-160 mg orally daily for 6-10 weeks improves anxiety when compared with placebo. However, heterogeneity and small sample sizes limit the validity of these findings (58077,58080,58098,95640,103061,103069). A meta-analysis of a subgroup of these clinical studies shows that taking Silexan 80 mg orally once daily for 10 weeks also reduces anxiety in patients with subthreshold anxiety disorders, which meet some but not all criteria for generalized anxiety disorder (97257). Limited research compares Silexan to the conventional medications paroxetine and lorazepam. One clinical study shows that taking Silexan 80 mg daily for 6 weeks improves anxiety and quality of sleep similarly to low-dose lorazepam (Ativan) 0.5 mg in adults with generalized anxiety disorder (58077). Another clinical study in adults with generalized anxiety disorder shows that taking Silexan 80-160 mg daily for 10 weeks reduces symptom severity similar to paroxetine 20 mg daily (93004). A network meta-analysis suggests that the higher dose of Silexan (160 mg) might be more effective when compared with paroxetine 20 mg or lorazepam 0.5 mg (103069). Limited research has assessed other oral formulations of lavender. A small clinical study in postmenopausal adults with mild to moderate anxiety shows that taking a dried lavender flower powder 500 mg twice daily for 8 weeks reduces anxiety by about 6% when compared with placebo, as measured on the State-Trait Anxiety Inventory Scale (97256). The clinical significance of this improvement is not clear. Meta-analyses of clinical trials in patients with chronic or situational anxiety show that inhalation aromatherapy or aromatherapy massage using lavender oil moderately reduces anxiety when compared with control. Most often, the control group received no intervention although occasionally they received standard or routine care. In some studies, plain water or diluted lemon juice were used as controls. Most treatments with lavender aromatherapy were given as single sessions of 1-30 minutes. However, occasionally multiple sessions were used (101720,103061,109974). Most other individual clinical trials of aromatherapy with lavender, alone or in combination with bergamot, are in agreement with these findings (58103,95637,97258,99713,101722,101724,108752,109854,109981), although some research does not support the use of lavender aromatherapy for anxiety (29504,58053,97258,101724,109853). The poor quality of most of the available research makes it difficult to determine which patients, if any, are most likely to benefit.
• Depression. Oral lavender, in the form of tea, tincture, powder, or a specific oil (Silexan), seems to reduce depressive symptoms in some patients. Early research also shows that lavender oil aromatherapy seems to improve symptoms of depression. Details: When used orally, lavender may be beneficial in some patients with depression. A meta-analysis of five clinical trials shows that oral lavender is moderately more beneficial than a control group for reducing symptoms of depression (109860). Most studies included in the analysis were low- to moderate-quality with variation in patient demographics. Studies in the analysis investigated the effects of oral lavender oil or powder in menopausal or postpartum patients, or in patients with major depression, and compared lavender with routine care, placebo, medication, or no intervention. Doses have included powdered lavender leaves 1-2 grams daily for 8 weeks, lavender tea made from 2 grams powder per teabag once or twice daily for 2 weeks, and a specific oral capsule containing lavender oil (Silexan, Dr. Willmar Schwabe GmbH & Co. KG) 80 mg daily for 70 days (103060,104433,109860). Other preliminary clinical research in patients with depressed mood shows that taking Silexan 80 mg daily for 6 weeks can improve depression scores by about 33% when compared to baseline (58098). Also, a small clinical study in patients with mild to moderate depression shows that drinking a tincture of lavender appears to be slightly less effective than imipramine; however, lavender might have some additive antidepressant effects when used in combination with imipramine (9792). The validity of these findings is limited by the lack of a placebo group and small study size. Lavender has also been taken in combination with other products. A small clinical study in patients with depression and anxious distress shows that taking 5 mL of a syrup containing lavender flower extract and Chinese dodder extract twice daily for 6 weeks seems to reduce depression to a similar degree as citalopram 20 mg daily (104437). It is unclear if the benefit is due to lavender, Chinese dodder, or the combination. Lavender oil aromatherapy has also been evaluated. A meta-analysis of nine clinical trials shows that lavender oil aromatherapy is moderately more beneficial than control for reducing symptoms of depression. Most studies included in the analysis were low- to moderate-quality with variation in patient demographics. Studies in the analysis investigated the effects of lavender oil aromatherapy in a variety of patient populations, and no studies were specific to patients with depression. Lavender aromatherapy was compared with no intervention, routine care, other aromatherapy oils, or distilled water (109860). However, in hospitalized patients undergoing microvascular breast reconstruction, lavender oil aromatherapy does not improve symptoms of perioperative depression when compared with coconut oil (109853). Lavender oil has also been studied in combination with other oils as aromatherapy. A small clinical study in community-dwelling older adults shows that inhalation or massage with lavender, sweet orange, and bergamot oils twice weekly for 8 weeks improves depressive symptoms in 55% to 65% of patients when compared with a control (98474). Another small clinical study in postmenopausal adults shows that a combination of aromatherapy with lavender and bergamot oils three times daily for 8 weeks along with routine care modestly improves symptoms of depression when compared with routine care alone (109981). It is unclear if any benefit is due to lavender, other ingredients, or the combination.
• Dysmenorrhea. Limited clinical research suggests that lavender oil aromatherapy might reduce dysmenorrhea symptoms. Details: A clinical study in young adults with dysmenorrhea shows that applying 3 drops of lavender oil to a piece of cotton and inhaling for 30 minutes daily for the first 3 days of menstruation modestly reduces pain when compared to inhaling the scent of diluted milk (95635). Another small clinical study in patients with dysmenorrhea shows that applying 3 drops of lavender oil to the hands and inhaling for 5 minutes every 6 hours for the first 3 days of menstruation seems to reduce abdominal pain and backache when compared with inhaling the scent of sesame oil (90510). Lavender oil has also been added to abdominal massage. A clinical crossover study in young females with dysmenorrhea shows that administering a gentle abdominal massage with lavender essential oil for 15 minutes moderately reduces pain immediately after treatment when compared with a massage with petrolatum (58106). It is unclear if the benefit persists after the end of the treatment. Additionally, because all available research has been conducted in the Middle East, it is unclear if these results can be extrapolated to other geographic locations.

POSSIBLY INEFFECTIVE

• Cancer-related pain. Using lavender oil for massage or as an aromatherapy diffusion does not seem to provide any additional pain relief in patients with advanced or terminal cancer. Details: Clinical research in patients with advanced or terminal cancer shows that diffusing lavender oil as aromatherapy or using lavender oil for massage does not improve pain scores when compared with control treatments without lavender oil (29504,58053).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alopecia areata. Topical lavender oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with alopecia areata shows that applying lavender oil in combination with essential oils from thyme, rosemary, and cedarwood daily for 7 months seems to improve hair growth in 44% of participants when compared with 15% of those using only carrier oils (5177). It is unclear if this effect is due to lavender oil, other oils, or the combination.
• Atopic dermatitis (eczema). Although there is interest in using topical lavender oil for eczema, there is insufficient reliable information about the clinical effects of lavender oil for this condition.
• Burns. It is unclear whether lavender oil aromatherapy is beneficial as adjunct treatment for reducing pain associated with dressing changes in children with burns. Details: Preliminary clinical research in young children with second-degree burns shows that lavender oil aromatherapy, provided as 0.5 mL dripped onto a gauze pad and placed 20 cm away from the child's nose for 15 minutes before a dressing change, modestly reduces pain severity at 1 and 30 minutes after the dressing change when compared with placebo aromatherapy with jojoba oil. Use of lavender oil aromatherapy also attenuated increases in heart and respiratory rates after the dressing change (109857).
• Canker sores. Topical lavender oil might improve canker sore healing and reduce swelling and pain. Details: A clinical study shows that applying 2 drops of lavender oil to canker sores three times daily might reduce redness, swelling, and pain when compared with placebo (58099).
• Colic. It is unclear whether lavender oil aromatherapy massage is beneficial for reducing colic symptoms in infants. Details: A small clinical trial shows that using lavender oil diluted with almond oil to massage the belly of infants for 5-15 minutes beginning at the onset of colic reduces average weekly crying times by about 7 hours when compared with infants not receiving aromatherapy massages (58096). It is unclear if this effect is due to lavender oil, massage, or the combination.
• Coronary artery bypass graft (CABG) surgery. Small clinical studies suggest that lavender aromatherapy might modestly improve sleep and reduce pain in patients who have undergone CABG surgery. Details: One small clinical study shows that placing three drops of lavender oil (Barich Essence Company) on the pillow every night for 5 nights modestly improves sleep quality, but not sleep latency, duration, or efficiency, when compared with placebo (109861). Another small clinical study shows that placing 2 drops of lavender oil on a cotton ball for overnight aromatherapy starting on the second evening after surgery modestly improves sleep quality on the second and third nights of use, but not the first night, when compared with distilled water (109856). Also, a small clinical study shows that applying 5 drops of lavender oil 20% to a gauze which is worn around the neck for 30 minutes after CABG surgery modestly reduces postoperative pain on the day of surgery and the day after surgery when compared with pre-aromatherapy pain levels. These changes were greater than those seen in patients inhaling distilled water (109850). However, one small clinical study shows that inhaling 2 drops of lavender oil 2% for 20 minutes on postoperative days 2 and 3 does not reduce mental stress when compared with placebo (93009).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral lavender is beneficial for olfactory dysfunction in patients with COVID-19. Details: A small preliminary clinical trial in patients with olfactory dysfunction related to COVID-19 shows that taking lavender syrup 9 mL twice daily for 3 weeks in combination with routine treatments modestly reduces symptoms when compared with routine treatments alone. However, there was no change in symptom scores or the percentage of patients with complete improvement in olfactory or taste dysfunction. The lavender syrup was made by preparing a water extract of the dried aerial parts and mixing with honey and water (109864).
• Dementia. Small clinical studies suggest that diffused aromatherapy with lavender oil may modestly improve agitation symptoms in patients with dementia; however, lavender oil applied to the patient or the patient's clothes might not be beneficial. Details: Some small and heterogeneous clinical studies in patients with dementia show that applying lavender oil aromatherapy via a diffuser for either 20 minutes twice daily, 2 hours daily, or once nightly for up to 3 weeks seems to improve agitation when compared with baseline, water, or a sunflower oil placebo (16393,58052,95632). However, using aromatherapy that is applied to the person's clothes or arms does not seem to help. Small clinical studies in patients with moderate or advanced dementia show that applying lavender oil to a pad attached to a patient's shirt does not reduce agitation when compared with placebo (12213,99710). Another clinical study in nursing home residents with dementia and frequent agitated behavior shows that applying 1 mL of 30% lavender oil to each forearm does not reduce agitation or improve mood when compared with applying placebo oil (93014).
• Diabetic neuropathy. It is unclear if lavender aromatherapy massage is beneficial for diabetic neuropathy. Details: Preliminary clinical research in patients with neuropathic pain related to diabetes shows that a gentle foot massage with lavender essential oil 3% in sunflower oil for 10 minutes nightly for 1 month reduces neuropathic pain and improves quality of life when compared with a placebo sunflower oil massage or routine care alone (109858).
• Fall prevention. It is unclear if lavender aromatherapy prevents falls in elderly patients. Details: A clinical study in nursing home residents aged 65 years or older shows that attaching a patch with lavender oil (Aromaseal Lavender, Hakujuji Co.) onto the neckline of clothing once daily for one year seems to have a non-significant trend toward reduced fall incidence when compared with placebo (58101).
• Fatigue. Small clinical studies suggest that lavender aromatherapy may modestly reduce fatigue in patients with underlying medical conditions, such as kidney failure or heart disease. The effects of lavender for fatigue in otherwise healthy adults is unclear. Details: Most small clinical studies in adults with kidney failure show that receiving aromatherapy with lavender essential oil during hemodialysis sessions for 4 weeks reduces fatigue when compared with baseline, a control group, or a placebo group (98524,109867). However, one small clinical study in these patients shows that applying lavender oil for inhalation for 10 minutes during dialysis sessions for 4 weeks does not reduce fatigue when compared with control (95642). Lavender aromatherapy has also been tried in patients hospitalized with various forms of cardiac disease. A small clinical trial shows that placing 3 drops of lavender oil on a cotton ball and inhaling for 20 minutes nightly for 7 days improves fatigue scores by 21 points, compared with a 2-point improvement in those receiving placebo (107959). The validity of these findings is limited due to the short duration of treatment.
• Hypertension. Although there is interest in using lavender aromatherapy for hypertension, there is insufficient reliable information about the clinical effects of lavender for this condition.
• Insect repellent. Although there is interest in using topical lavender to repel insects, there is insufficient reliable information about the clinical effects of lavender for this condition.
• Insomnia. Inhalation aromatherapy or aromatherapy massage with lavender oil may improve some subjective measures of sleep, but results are conflicting and improvements appear minimal at best. Additionally, most small clinical studies suggest it does not improve sleep in hospitalized patients. Details: Lavender oil aromatherapy seems to improve sleep quality in some patients, although it is unclear which patient populations may be most likely to be benefit. A clinical study in healthy college students with self-reported sleep problems shows that wearing a patch containing lavender oil 55 mcL on the chest, in addition to practicing sleep hygiene, improves self-reported sleep quality, but not sleep quantity, when compared with wearing a placebo patch (93012). Another small clinical study in elderly patients that have trouble sleeping in nursing homes shows that placing 2 drops of lavender oil to a cotton pad on a nightstand at bedtime for 4 weeks moderately improves sleep quality and reduces fatigue when compared with control (103062). A meta-analysis of three clinical trials shows that lavender modestly improves postpartum sleep quality when compared with control, including placebo or no intervention. However, each trial used a different form of lavender, including a topical cream, a tea, and aromatherapy. Also, the individual trials included in the analysis show that only the cream and aromatherapy resulted in statistically significant improvements in sleep quality (109866). Conversely, a small clinical study in postmenopausal adults with insomnia who received sleep hygiene guidance shows that inhaling lavender oil 6% before bed nightly for 1 month does not improve sleep quality when compared with sunflower oil. The oil was inhaled from the bottle for two, two-minute sessions and then poured on a cotton ball and placed near the head while sleeping (109852). Lavender aromatherapy has also been evaluated for insomnia in patients with comorbid disease states. A clinical study in patients with insomnia and type 2 diabetes shows that lavender oil aromatherapy for 5 minutes at bedtime nightly for 4 weeks improves sleep when compared with almond oil (103065). Preliminary clinical research in adults with kidney failure shows that foot massage with lavender oil 1.5% for 3 weeks during hemodialysis modestly improves sleep quality when compared with routine care, but is no more effective than sweet orange oil (109859). Another preliminary clinical study in cancer patients shows that receiving aromatherapy as two drops of pure lavender oil applied to a cotton ball and attached to the collar for 20 minutes at bedtime for one week improves sleep when compared with baseline, but seems to be no better than using peppermint oil or a lavender oil 1% control (103063). The validity of this finding is limited because the lavender oil 1% control resulted in notable benefit and might have been an inadequate control treatment. Aromatherapy with lavender oil does not seem to improve sleep in most hospitalized patients, including patients in intermediate care units, hospitalized cardiac patients, and in patients undergoing microvascular breast reconstruction. Aromatherapy treatments have included lavender aromatherapy throughout hospitalization, placing 3 mL of lavender oil 3 feet away from the bed during sleep, and hand and lower leg massage with lavender essential oil 1.5% in sweet almond oil at bedtime (93013,101727,109853). However, studies have generally been small and did not use proper controls. Also, some small clinical studies suggest that lavender aromatherapy might have modest beneficial effects in patients undergoing coronary artery bypass graft (CABG) surgery (109856,109861).
• Kidney failure. Small clinical studies suggest that lavender aromatherapy may modestly reduce fatigue and improve sleep quality in adults receiving hemodialysis. Lavender oil massage may also modestly improve symptoms of restless leg syndrome (RLS) in these patients. Details: Multiple small studies have evaluated lavender aromatherapy, provided during hemodialysis sessions, for reducing fatigue. A small clinical study shows that applying 5% lavender essential oil (Barij Essence Pharmaceutical Company) to a cotton ball on the patient's collar for inhalation for 15-20 minutes twice daily during each session for 1 month reduces fatigue by an additional 44% and 40% when compared with baseline and control, respectively (98524). Another preliminary clinical trial shows that applying lavender oil 7% in sweet almond oil to a gauze pad placed 20 cm from the patient's nose for 2 minutes improves fatigue when compared with placebo aromatherapy. By the third week of four total weeks of treatment, most patients given lavender oil aromatherapy had only mild fatigue, compared with moderate or severe fatigue in the control group (109867). Also, a small clinical trial shows that aromatherapy or aromatherapy foot massage with lavender and sweet orange oil for 10-20 minutes during each session for 2 months reduces fatigue when compared with no treatment. Aromatherapy massage seems to be more effective than aromatherapy alone (103068). However, one small clinical study shows that applying the oil for inhalation for 10 minutes during each session for 1 month does not reduce fatigue when compared with control (95642). The difference in these findings might be due to study size, lavender oil concentration, or the frequency and duration of aromatherapy sessions. Lavender aromatherapy has also been evaluated for reducing insomnia in adults on hemodialysis. A small clinical study shows that foot massage with lavender oil 1.5% for 3 weeks during hemodialysis sessions modestly improves sleep quality when compared with routine care. However, it does not seem to be more effective than using sweet orange oil (109859). Some small clinical studies in patients undergoing hemodialysis show that massaging the feet or lower legs with lavender oil reduces the severity of RLS by up to 45% when compared with routine care, massage only, or baby oil as placebo (95638,103064,109865). However, massage with lavender oil does not seem to be more beneficial than glycerin oil 2% or sweet orange oil 1.5% for reducing RLS severity (103064,109859). Doses have included 10-15 mL of 1.5% or 5% lavender oil for 10- to 45-minutes during hemodialysis sessions for 3-4 weeks (95638,103064,109859,109865).
• Labor pain. Lavender aromatherapy may help to reduce pain during childbirth. Details: A meta-analysis of clinical trials in pregnant patients in Iran shows that lavender oil aromatherapy applied by various means, such as mask or massage, reduces labor pain when compared with control (104440). All available research has been conducted in Iran, so it is unclear if the benefit can be extrapolated to other geographic locations.
• Lice. Topical lavender oil has only been evaluated in combination with other essential oils; its effect when used alone is unclear. Details: Clinical studies in patients with head lice shows that applying lavender oil in combination with tea tree oil reduces the number of hatched and unhatched live lice when compared with control (19188,19189). When applied with tea tree oil three times weekly, lavender oils seems to improve lice eradication when compared with two weekly treatments of pyrethrin and piperonyl butoxide (19189). It is not known if these effects are due to tea tree oil, lavender, or the combination.
• Menopausal symptoms. It is unclear if lavender aromatherapy reduces menopausal symptoms such as hot flushes. Details: A meta-analysis and individual clinical studies in postmenopausal adults show that lavender aromatherapy for 4-12 weeks, alone or in combination with other essential oils, reduces menopausal symptoms such as hot flushes when compared with placebo (95634,99711,103067). However, heterogeneity and small sample sizes limit the validity of these findings. A small clinical study in postmenopausal adults shows that aromatherapy with lavender 2% oil for 20 minutes at bedtime every day for 1 month improves quality of life scores when compared to baseline (99711). Another small clinical study in menopausal adults shows that receiving aromatherapy with lavender oil and lemon oil for 5 minutes daily for 30 days seems to improve sleep and quality of life when compared with placebo (104439). However, a small clinical study in postmenopausal adults shows that a combination of lavender and bergamot oils administered via inhalation three times daily for 8 weeks with routine care does not improve sexual function when compared with routine care alone (109981).
• Migraine headache. It is unclear if lavender aromatherapy improves migraine symptoms. Details: A small clinical study in patients with migraine headaches shows that rubbing 2-3 drops of lavender oil on the upper lip for inhalation might reduce headache pain and associated symptoms such as nausea and photophobia. Of 129 headaches treated with lavender oil, 92 responded completely or partially, compared with 32 of 68 headaches in the placebo group (18209).
• Multiple sclerosis (MS). It is unclear if lavender aromatherapy can improve memory in patients with MS. Details: A small preliminary clinical trial in patients with MS shows that dripping 2 drops of lavender oil (Barij Essence Pharmaceutical Company) on a cotton ball for inhalation for 10 minutes twice daily for 2 weeks improves working memory by a small amount when compared with inhaling distilled water (109855).
• Multiple sclerosis-related fatigue. It is unclear if oral lavender is beneficial for reducing fatigue in adults with multiple sclerosis (MS). Details: A small clinical trial in patients with MS shows that taking lavender 600 mg three times daily for 60 days improves fatigue by a large amount when compared with placebo (109851).
• Neuropathic pain. Although there is interest in using topical lavender oil for neuropathic pain, there is insufficient reliable information about the clinical effects of lavender for this condition.
• Osteoarthritis. It is unclear if lavender aromatherapy with massage reduces osteoarthritis pain. Details: A small clinical study in patients with osteoarthritis shows that applying 5 mL of 3% lavender oil (Barij Essence Pharmaceutical Company) to the knee through self-administered massage three times weekly for 3 weeks can reduce pain by 23% when compared to massage with placebo oil and by 36% when compared with no treatment. However, any benefits of treatment begin to wear off after treatment completion (95645).
• Otitis media. Topical lavender oil has only been evaluated in combination with other essential oils; its effect when used alone is unclear. Details: A clinical study in children ages 5-18 years with otitis media and otalgia shows that administering ear drops containing lavender and other herbal extracts, alone or in combination with a topical anesthetic, improves ear pain when compared with baseline. However, it is possible that the pain is self-limited and any pain reduction is due to natural resolution (39500).
• Pain (acute). Small clinical studies suggest that lavender aromatherapy may modestly reduce acute pain from needle insertion or other procedures in infants and adults. Details: Two small clinical studies in patients having a needle inserted for hemodialysis shows that inhaling 10% lavender essence for 5 minutes or topically applying 0.3 mL of 100% lavender oil for 5 minutes prior to needle insertion modestly reduces pain when compared with using placebo oil or water (93008,93010). Lavender aromatherapy has also been tried for gynecological exam pain. A clinical study shows that inhaling 10% lavender oil from a heat lamp for 10-15 minutes prior to gynecological exams can reduce pain experienced during the exam up to three-fold when compared to those receiving no treatment (95639). Lavender oil aromatherapy may also reduce vaccination, needle stick, and heel-lancing pain in infants. One clinical study shows that inhaling the scent of lavender oil (Barij Essence Pharmaceutical Company) 0.5% drops for one minute before vaccination modestly reduces pain and decreases crying time by about 20 seconds when compared with sweet almond oil (109869). A small clinical study in term infants shows that being placed in an incubator with lavender essential oil scent overnight before receiving a blood draw modestly reduces overall pain scores when compared with no intervention, but seems to be no different than giving 2 mL of 30% glucose solution (103066). Another small clinical study in premature infants shows that inhaling the scent of 6 lavender oil drops on a cotton ball for 3 minutes before and 30 seconds after a heel-lancing procedure seems to reduce pain scores when compared with exposure to an unscented cotton ball (104442). Lavender oil aromatherapy may also reduce pain due to frenotomy in infants. Preliminary clinical research shows that applying a gauze pad containing one drop of lavender oil under the nose, starting 2 minutes before the frenotomy and continuing throughout the procedure, modestly reduces pain when compared with routine care, which includes swaddling, oral sucrose, and pre-frenotomy sucking. Post-frenotomy crying was also reduced by about 50%, or 10 seconds (109868). Lavender oil seems to be similarly effective to vanilla oil (109810).
• Postdural puncture headache. It is unclear if lavender aromatherapy improves postdural puncture headache severity. Details: A small clinical study in patients with postdural puncture headache shows that receiving lavender oil aromatherapy for 15 minutes modestly improves pain immediately after treatment when compared with placebo. However, the pain relief is not maintained at 30 minutes after treatment (104441).
• Postoperative nausea and vomiting (PONV). It is unclear if lavender aromatherapy reduces PONV. Details: A small clinical study in postoperative patients shows that inhaling the scent of 2 drops of lavender oil from a cotton pad for 5 minutes improves nausea scores in 83% of people, compared with 44% of those inhaling a placebo. There was no difference in vomiting scores between groups (99712). Another small clinical study in patients after percutaneous nephrolithotomy shows that inhaling the scent of 3 drops of lavender essential oil from a gauze for 5 minutes immediately after the operation, and again 3 and 6 hours later, does not improve nausea or vomiting when compared with a control group that was not receiving aromatherapy (103872).
• Postoperative pain. The evidence for the use of lavender aromatherapy for pain after various types of surgical procedures is preliminary and conflicting. Details: Some preliminary clinical research in patients post-Cesarean section shows that, when used in conjunction with standard analgesic therapy, applying 2 drops of lavender oil 2% to a face mask or applying 3 drops of lavender to a cotton ball for inhalation seems to reduce postoperative pain when compared with control (58093,101724). Additionally, preliminary clinical research in patients undergoing coronary artery bypass graft (CABG) surgery shows that applying lavender oil to a gauze which is worn around the neck may modestly reduce postoperative pain on the day of surgery and the day after surgery when compared with distilled water (109850). Also, a small clinical study in children aged 6-12 years post-tonsillectomy shows that rubbing lavender oil onto the palms and inhaling for 3 minutes every 6 hours as needed reduces the use of acetaminophen when compared with control (90513). However, aromatherapy with lavender throughout hospitalization does not seem to improve postoperative pain in patients undergoing microvascular breast reconstruction when compared with coconut oil (109853).
• Postpartum complications. It is unclear if topical or inhaled lavender reduces postpartum complications such as pain and swelling. Details: Some clinical research in patients receiving an episiotomy during childbirth shows that adding lavender oil to water or sitz baths for up to 10 days might reduce episiotomy redness and discomfort when compared with using no lavender and standard treatment, such as povidone-iodine. However, findings are mixed as to whether adding lavender oil to baths helps to reduce edema and analgesic use (58085,58092,58116,58121). Lavender aromatherapy has also been studied to improve wellbeing in postpartum patients. A small clinical study in postpartum patients immediately following a natural birth shows that inhaling lavender oil from a cotton ball for 10-15 minutes in the morning, 6 hours later, and at bedtime, improves perceived pain, fatigue, distress, and mood within 1 hour of treatment and also the next morning when compared with placebo (95631).
• Postpartum depression. Small clinical studies suggest that aromatherapy with lavender oil may modestly improve or prevent depressive symptoms in postpartum patients. Details: A clinical study in healthy postpartum patients shows that placing 3 drops of lavender essential oil on the palms three times daily for 4 weeks after delivery moderately reduces depressive symptoms and anxiety when compared with usual care only (95637). There is limited research on the benefits of lavender aromatherapy in patients diagnosed with postpartum depression. A small clinical trial in these patients shows that a combination of lavender and rose essential oils, administered via inhalation or aromatherapy massage using hand "M" technique for 15-minute sessions, twice weekly for 4 weeks, reduces depression scores when compared with no intervention (58103).
• Pre-procedural anxiety. It is unclear if lavender aromatherapy can reduce preoperative or preprocedural anxiety; results from clinical research are generally of low-quality and benefits are modest at best. Details: A meta-analysis of four small clinical studies in patients undergoing cardiac surgery shows that lavender aromatherapy modestly reduces preoperative anxiety when compared with control (103058). However, the included studies were conducted in the Middle East, and it is unknown if these results are generalizable to other geographic areas. There is conflicting clinical evidence regarding the effect of lavender aromatherapy on anxiety prior to a dental procedure (58078,101725,103059). Small clinical studies also show mixed results as to whether lavender oil aromatherapy applied to a gauze bandage or oxygen mask improves anxiety in patients waiting for breast surgery when compared with usual care. (95641,101729). Lavender aromatherapy might reduce anxiety prior to less risky and extensive procedures such as needle injections. Small clinical studies in adults receiving botulinum toxin type A injections or children receiving dental injections show that lavender oil aromatherapy reduces heart rate and cortisol levels when compared with placebo (58089,104438). Another clinical study in preoperative patients undergoing insertion of a peripheral venous cannula shows that inhalation of 1% lavender oil (Talya Herbal Products) from a gauze pad for 5 minutes modestly reduces pain and anxiety scores and improves patient satisfaction when compared with control (95636). However, a clinical study in patients undergoing a colonoscopy or esophagogastroduodenoscopy shows that inhaling lavender oil does not reduce anxiety, although it does improve patient satisfaction, when compared with placebo (58066). Reasons for conflicting findings are unclear but may relate to the severity of anxiety, the specific outcomes measured, and cultural differences occurring in different geographic locations.
• Psychological well-being. It is unclear if topical or inhaled lavender improves well-being. Details: A small clinical study in healthy females shows that adding 3 mL of a mixture containing 20% lavender oil and 80% grapeseed oil to daily baths modestly improves mood when compared with baths containing grapeseed oil alone (15534). However, lavender may not impact well-being in patients with cancer. Clinical research shows that that adding lavender oil for an aromatherapy massage in patients with advanced or terminal cancer does not improve well-being or quality of life when compared with no massage treatment or massage with inert oil (29504,58053).
• Restless legs syndrome (RLS). Most preliminary clinical research suggests that lavender oil aromatherapy massage is beneficial for RLS in patients undergoing hemodialysis. Its effect in other patient populations is unclear. Details: Some small clinical studies in patients undergoing hemodialysis show that massaging the feet or lower legs with lavender oil reduces the severity of RLS by up to 45% when compared with routine care, massage only, or baby oil as placebo (95638,103064,109865). However, massage with lavender oil does not seem to be more beneficial than glycerin oil 2% or sweet orange oil 1.5% for reducing RLS severity (103064,109859). Doses have included 10-15 mL of 1.5% or 5% lavender oil for 10 to 45 minutes during hemodialysis sessions for 3-4 weeks (95638,103064,109859,109865).
• Stress. Small studies suggest that inhaled lavender oil does not reduce stress in students under academic stress. Details: A meta-analysis of 21 moderate- to high-quality, small- to medium-sized studies shows that inhaling lavender oil modestly reduces stress when compared with control. Most studies included in the analysis have used lavender oil as aromatherapy; other studies have used a cream (109863). Also, inhaling lavender oil 3% in almond oil twice daily for 30 minutes during the exam period does not reduce academic stress or associated symptoms, including headache, blood pressure, or heart rate, in pharmacy students when compared with inhaling an odorless oil, although both were more effective than no intervention (101723).
• Toothache. Although there is interest in using topical lavender oil for toothache, there is insufficient reliable information about the clinical effects of lavender oil for this purpose. More evidence is needed to rate lavender for these uses.

(Read more about LAVENDER)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• ACE inhibitor-induced cough. It is unclear if oral marshmallow root is beneficial in patients with cough due to ACE inhibitors. Details: A small clinical study in patients with ACE inhibitor-induced cough shows that taking marshmallow root 40 mg (20 drops) three times daily for 4 weeks improves cough when compared to baseline (62027). The validity of this finding is limited by the lack of a control group.
• Atopic dermatitis (eczema). It is unclear if topical marshmallow is beneficial in children with eczema. Details: A very small clinical study in children ages 3 months to 12 years with a recent diagnosis of mild to moderate eczema shows that applying a marshmallow 1% ointment twice daily for 1 week and then three times weekly for 3 weeks seems to reduce symptoms, as measured on the SCORing Atopic Dermatitis (SCORAD) scale, when compared with applying hydrocortisone 1% ointment (105437). This finding is limited by the large number of drop-outs due to non-compliance, most of which were in the marshmallow group.
• Breast engorgement. It is unclear if topical marshmallow is beneficial in women with this condition. Details: A small clinical study in breastfeeding women with breast engorgement shows that applying a compress containing 40-50 mL of a solution made from marshmallow leaves and stems 3 times daily for 2 days in conjunction with standard treatment improves patient-reported breast engorgement scores when compared with standard treatment alone. Standard treatment consisted of massage and alternating warm and cold compresses before and after breastfeeding (92845).
• Constipation. Although there is interest in using oral marshmallow for constipation, there is insufficient reliable information about the clinical effects of marshmallow for this condition.
• Cough. Although there is interest in using oral marshmallow for cough, there is insufficient reliable information about the clinical effects of marshmallow for this condition.
• Diarrhea. Although there is interest in using oral marshmallow for diarrhea, there is insufficient reliable information about the clinical effects of marshmallow for this condition.
• Fever. It is unclear if topical marshmallow is beneficial for pediatric fever. Details: A moderate-sized clinical study in children aged 6 months-10 years with fever receiving rectal acetaminophen shows that applying marshmallow extract body wash and lukewarm water reduces the time to defervescence by 8 minutes when compared with lukewarm water alone, but does not improve the change in body temperature, number of acetaminophen doses given, or incidence of fever recurrence (112375). However, the interpretation of these findings is limited to patients without fevers greater than 40 degrees Celsius or history of febrile seizures since these patients were not studied.
• Leishmania lesions. Topical marshmallow has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research suggests that the topical application of an herbal extract containing a combination of marshmallow and Althaea rosa to affected areas for 5 days can help promote curing of Leishmania lesions (62020).
• Respiratory tract infections. Although there is interest in using oral marshmallow for respiratory tract infections, there is insufficient reliable information about the clinical effects of marshmallow for this condition.
• Vaginal candidiasis. It is unclear if vaginal marshmallow is beneficial for vulvovaginal candidiasis. Details: A small clinical study in adults with vulvovaginal candidiasis shows that applying a vaginal cream comprised of marshmallow extract 4% and clotrimazole 1% daily for 7 days improves itching, dyspareunia, and dysuria at 7 days when compared with clotrimazole 1% alone. At 30 days, the marshmallow intervention also results in fewer positive yeast cultures and sustained reduction in itching (112371). However, the validity of these results is limited by significant differences between groups at baseline for dyspareunia and dysuria, and lack of adjustment for multiple comparisons which can increase false positive findings. Additionally, all primary outcomes were patient-reported.
• Venous leg ulcers. Although there is interest in using topical marshmallow for venous leg ulcers, there is insufficient reliable information about the clinical effects of marshmallow for this condition.
• Wounds. Although there is interest in using topical marshmallow for wounds, there is insufficient reliable information about the clinical effects of marshmallow for this condition. More evidence is needed to rate marshmallow for these uses.

(Read more about MARSHMALLOW)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Headache. Although there has been interest in using oral meadowsweet for headache, there is insufficient reliable information about the clinical effects of meadowsweet for these conditions.
• Respiratory tract infections. Although there has been interest in using oral meadowsweet for respiratory tract infections, including cold, flu, bronchitis, and pneumonia, there is insufficient reliable information about the clinical effects of meadowsweet for these conditions. More evidence is needed to rate meadowsweet for these uses.

(Read more about MEADOWSWEET)

LIKELY EFFECTIVE

• Irritable bowel syndrome (IBS). Oral enteric-coated peppermint oil is conditionally recommended by the American College of Gastroenterology (ACG) for the relief of global IBS symptoms, such as abdominal pain. Details: The ACG conditionally recommends the use of peppermint for the relief of global IBS symptoms. This recommendation is based on an available meta-analysis of generally low-quality clinical research (105124). Several clinical trials and meta-analyses show that taking enteric-coated peppermint oil 1-2 capsules orally two to four times daily reduces abdominal pain, distention, flatulence, and bowel movements in patients with IBS. Each capsule provides approximately 0.2 mL of peppermint oil or 180-225 mg peppermint oil. Most trials have used specific products (Colpermin, Tillotts Pharma; Mintoil, Cadigroup; Ibgard, IM HealthScience, Tempocol) (3802,3803,4469,11778,11779,17681,17682,68467,68515,68522)(68603,68604,68605,96360,99493,109980). The most recent meta-analysis to date shows that four patients would need to take peppermint oil to prevent one patient from having persistent IBS symptoms, and seven patients would need to take peppermint oil to prevent one patient from having abdominal pain. However, the individual studies included in the analysis lasted no more than 12 weeks (109980); any long-term effects are unclear. Although most studies have shown benefit for reducing symptoms, some older studies have found no significant effect (11777,11789) or only short-term benefits (68620). Also, a well-designed study shows that taking peppermint oil capsules designed for either small intestinal release (enteric-coated) or ileocolonic release does not increase the number of people with at least a 30% decrease in abdominal pain over a period of 4 weeks, although symptoms are modestly reduced when compared with placebo (102602). Another clinical trial in patients with moderate to severe IBS shows that taking a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) 180 mg three times daily for 6 weeks does not further improve symptom severity when compared with placebo. However, both groups experienced a large improvement on the IBS-Severity Scoring System (IBS-SSS) and the IBS Global Improvement Scale (107955). The validity of these findings is limited due to lost data and inconsistent follow-up; additionally, adverse effects occurred more frequently in the peppermint oil group. The reasons for these negative findings are unclear but may include short treatment durations and the use of different formulations; additionally, IBS is comprised of various subtypes and symptoms that can range in severity and presentation, which may alter treatment response. Some clinical research has also evaluated a specific combination product (Atrantil, KBS Research) containing peppermint leaf, red quebracho extract, and conker tree extract. Taking this product as needed for 2 weeks seems to reduce constipation and bloating when compared to baseline in patients with constipation-predominant IBS (95429,95430). It is unclear if the effects of this product are due to peppermint, the other ingredients, or the combination.

POSSIBLY EFFECTIVE

• Barium enema-related colonic spasm. Rectal peppermint, as part of barium enema preparations, seems to reduce colonic spasms during examination. Oral peppermint also seems to be beneficial. Details: Rectal use of peppermint oil, added as an ingredient in barium enema preparations, seems to relax the colon during barium enema examination and reduce the percentage of patients who experience colonic spasms by about 25% to 30% (6739,6749,12009). Adding peppermint oil to the barium enema seems to be at least as effective as using systemic scopolamine (Buscopan). Adding peppermint oil to the barium solution also does not seem to impair image quality (12009). Some clinical research also shows that taking peppermint oil orally before the start of a double-contrast barium enema examination decreases spasms and might also increase diagnostic quality (14467).
• Chemotherapy-induced nausea and vomiting (CINV). Oral and inhaled peppermint seem to reduce nausea and vomiting in patients with CINV. Details: Clinical research shows that adding peppermint oil, 40 drops in 20 mL water, every 8 hours following chemotherapy treatment to treatment with standard antiemetics reduces the severity of nausea, vomiting, and anorexia by moderate to large amounts over 48 hours when compared with a plain water placebo (105123). The use of peppermint oil aromatherapy has also been investigated. Clinical research shows that adding 2 drops of peppermint oil to a cool, damp washcloth for use on the neck as aromatherapy for about 30 minutes helps relieve chemotherapy-induced nausea by a small amount when compared with a washcloth without peppermint oil (102603). Additional clinical research in patients receiving standard antiemetics after chemotherapy shows that applying one drop of peppermint oil below the nose three times daily for 5 days reduces the severity of nausea and the frequency of nausea, vomiting, and retching by a moderate to large amount when compared with the antiemetics alone. These parameters were not improved following treatment with cisplatin (105122). In children with acute leukemia, a small clinical study shows that aromatherapy with 2 drops of peppermint oil and 3 drops of lemon oil in 80 mL of water diffused 30 minutes prior to and 2 and 4 hours after chemotherapy once weekly for 4 weeks decreases the severity of nausea, vomiting, and retching, and improves quality of life scores when compared with diffused water or no intervention (112015). The validity of these findings is limited by the use of patient-reported outcomes.
• Dyspepsia. Oral peppermint, in combination with caraway and possibly other ingredients, seems to reduce symptoms of dyspepsia. It is unclear if oral peppermint alone is beneficial. Details: Some clinical research shows that taking specific products containing peppermint and caraway oil (Enteroplant, Dr Willmar Schwabe Pharmaceuticals; Menthacarin, Dr Willmar Schwabe GmbH & Co.) improves quality of life and reduces symptoms of dyspepsia, including feelings of fullness, pain, and mild gastrointestinal spasms (6740,6741,10075,96344,102600). A meta-analysis of three of these clinical studies shows that taking this combination product 2-3 times daily for 4 weeks modestly reduces abdominal pain when compared with placebo (110091). Taking this combination twice daily for 4 weeks also improves postprandial distress syndrome and epigastric pain syndrome, two subtypes of dyspepsia, when compared with placebo (96344). The combination of enteric-coated peppermint oil 90 mg and caraway oil 50 mg appears to be comparable to cisapride for relieving dyspepsia when taken 2-3 times daily for up to 4 weeks (6740,6741,10075). However, most trials investigating this combination are small and/or of overall low quality (102600). A specific combination product containing peppermint leaf (Iberogast, Steigerwald Arzneimittelwerk GmbH) also seems to improve symptoms of dyspepsia. The combination includes peppermint leaf plus clown's mustard plant, German chamomile, caraway, licorice, milk thistle, angelica, celandine, and lemon balm (7049). A meta-analysis of studies using this combination product shows that taking 1 mL orally three times daily over a period of 4 weeks reduces the severity of acid reflux, epigastric pain, cramping, nausea, and vomiting when compared with placebo (13089). A similar combination product containing extracts from peppermint leaf, clown's mustard plant, German chamomile flower, caraway, licorice root, and lemon balm (STW 5-II, Steigerwald Arzneimittelwerk GmbH) 1 mL taken three times daily for up to 8 weeks eliminates gastrointestinal symptoms in 40% more dyspepsia patients when compared with placebo (12724).
• Endoscopy-associated adverse effects. Intraluminal peppermint seems to reduce spasticity during an endoscopy. It is unclear if oral peppermint is beneficial for reducing adverse effects related to endoscopy. Details: A meta-analysis of four clinical trials show that peppermint oil, administered orally or intraluminally, reduces the incidence of spasticity by about 41% when compared with placebo in patients undergoing endoscopy, with severe spasticity occurring at about 30% the rate of those taking placebo. However, there was no effect on subjective pain (102604). Individual clinical studies show that intraluminal peppermint oil can reduce both pain and spams in patients undergoing endoscopy (18220,68371,68395,68445,68532). However, there are limitations with this form of administration, including cost and practicality, which has led to interest in the use of oral formulations (104221). Studies evaluating oral extended-release peppermint have been conflicting. While one study shows that a specific extended-release peppermint oil product (Colpermin) 187 mg or 0.2 mL taken orally 4 hours prior to a colonoscopy reduces procedure time, pain, and spasticity (68532), a study using another specific extended-release peppermint oil (IBGard) did not show an effect on colonic spasms, procedure time, or adenoma detection rate when compared with placebo (104221). These differing outcomes may be due to timing of administration. The study that showed benefit administered the treatment 4 hours prior to endoscopy, whereas the study showing no benefit administered the treatment only 1 hour prior. This suggests that extended-release peppermint may need to be administered at least 4 hours prior to the procedure to allow for adequate colonic release (68532,102604,104221).
• Nipple fissures. Topical peppermint seems to reduce cracked skin and pain in the nipples due to breastfeeding. Details: Clinical research shows that topical application of peppermint oil in gel or water reduces cracked skin and pain in the nipple area from breastfeeding when compared with using placebo, lanolin, or the expressed breast milk technique (68454,68462). Other research shows that applying peppermint oil in cream immediately after breastfeeding for 2 weeks decreases pain and trauma in the nipple area similarly to the topical application of dexpanthenol or lanolin (96365).
• Pressure ulcers. Topical peppermint seems to reduce the risk of pressure ulcers. Details: Clinical research in bedridden patients shows that prophylactic application of a topical gel containing peppermint oil 0.2% three times daily for up to 14 days results in pressure injuries in about 23% of patients compared with 77% of those given a placebo gel (102605).
• Tension headache. Topical peppermint seems to relieve tension headaches. Details: Clinical research shows that topical application of peppermint oil 10% relieves tension headaches when compared with placebo (3801,6190).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Abdominal pain. Although there has been interest in using oral peppermint for abdominal pain, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety. Details: A clinical trial in patients presenting to the emergency department for an acute coronary syndrome event shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 1 hour improves anxiety and respiratory rate when compared with baseline or placebo (107958). Due to the single-dose nature of this study, the effects of repeated inhalation of peppermint oil are unclear.
• Athletic performance. It is unclear if oral peppermint oil is beneficial for athletic performance. Details: Preliminary clinical research in trained adult runners shows that taking peppermint essential oil, 0.05 mL diluted in 500 mL of water, orally once 30 minutes before exercise improves running time to exhaustion by 11% when compared with placebo (112742).
• Breast cancer-related hot flashes. It is unclear if topical peppermint is beneficial for reducing hot flashes in patients with breast cancer. Details: Preliminary clinical research shows that using a spray containing a combination of peppermint and neroli hydrolat does not alleviate hot flashes in most patients receiving chemotherapy for breast cancer when compared with using a plain water spray (68481).
• Cognitive function. It is unclear if inhaled peppermint oil is beneficial for improving cognitive function. Details: Preliminary clinical research shows that inhalation of peppermint oil slightly improves memory and the performance of cognitive tasks such as typing, alphabetization, and ordering, but not attention and speed of task completion, when compared with control (56954,68416,68466).
• Common cold. Although there has been interest in using oral, topical, or inhaled peppermint for the common cold, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Dental plaque. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth for one minute with 10 mL of a specific combination product (HiOra, Himalaya Herbal Healthcare) containing peppermint oil and numerous other ingredients twice daily for two days reduces plaque index or plaque area when compared with placebo; however, it was not as effective as chlorhexidine 0.2% solution (68530). It is unclear if these effects are due to peppermint oil, other ingredients, or the combination.
• Diffuse esophageal spasm. It is unclear if oral peppermint oil is beneficial for diffuse esophageal spasm. Details: A small exploratory study in adults with diffuse esophageal spasm shows that drinking a solution of peppermint oil, 5 drops in 10 mL of water, can resolve esophageal contractions when compared with baseline (13415). The validity of this finding is limited by the lack of a comparator group.
• Dysmenorrhea. It is unclear if oral peppermint oil is beneficial for reducing menstrual pain. Details: Preliminary clinical research shows that taking three capsules of peppermint oil (Colpermin; Tillotts Company or Razak company) daily for 3 days, starting on the first day of menstruation, is as effective as mefenamic acid 250 mg three times daily for reducing pain, and more effective for reducing nausea and vomiting, associated with dysmenorrhea. However, mefenamic acid was more effective for reducing bleeding and analgesic use (105125).
• Fatigue. It is unclear if inhaled peppermint oil improves fatigue in patients with cardiac disease. Details: A clinical trial in hospitalized patients with various forms of cardiac disease shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 20 minutes nightly for 7 days improves fatigue scores when compared with placebo. These improvements were similar to those seen with lavender oil inhalation. Fatigue scores decreased by 24 and 21 points in the peppermint and lavender groups, respectively, compared with a 2-point reduction in the placebo group (107959). The validity of these findings is limited due to the short duration of treatment.
• Halitosis. Peppermint has only been evaluated in combination with other ingredients as a mouthwash; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth with a specific combination of tea tree oil, peppermint, and lemon essential oil once for three minutes improves breath smell when compared with placebo or benzydamine hydrochloride (19177). Other preliminary clinical research in elderly adults with dementia who require oral care assistance shows that cleaning the mouth with a mixture of peppermint oil, tea tree oil, and lemon essential oils diluted to 0.5%, applied via gauze, twice daily for 7 days improves halitosis scores and oral condition scores when compared with placebo (112957).
• Insomnia. It is unclear if inhaled peppermint oil is beneficial for insomnia. Details: Preliminary clinical research in cancer patients shows that receiving aromatherapy as three drops of peppermint oil applied to a cotton ball and attached to the collar for 20 minutes at bedtime for one week improves sleep when compared with baseline. However, it seems to be no better than using lavender oil aromatherapy or using a control of lavender oil 1% (103063).
• Menopausal symptoms. It is unclear if inhaled peppermint oil is beneficial for menopausal symptoms. Details: Preliminary clinical research in adults with menopausal symptoms shows that receiving aromatherapy as 2 drops of peppermint oil with upper extremity massage and for 30 minutes twice weekly for 4 weeks moderately improves menopause symptom scores, including both somatic symptoms and urogenital symptoms, when compared with placebo (112745).
• Migraine headache. It is unclear if intranasal or inhaled peppermint oil is beneficial for migraine headache. Details: Preliminary clinical research shows that using 1-2 doses of intranasal peppermint oil 1.5% (Poursina Company) at the start of migraine pain is as effective as intranasal lidocaine 4%, and more effective than placebo, for reducing migraine headache intensity. Approximately 42% of those using peppermint oil indicated a high level of headache reduction, compared with 42% of those using lidocaine and 5% of those using placebo. Also, pain relief was felt within 5 minutes in more patients using peppermint than placebo (105126). However, it is unclear if participants were truly blinded to the use of peppermint oil. Other preliminary clinical research in pediatric patients with migraine or other chronic headaches shows that receiving aromatherapy with peppermint oil over 10 minutes during a footbath does not improve pain or anxiety scores when compared with control (112746).
• Mosquito repellent. Although there has been interest in using topical peppermint oil as a mosquito repellent, there is insufficient reliable information about the clinical effects of peppermint for this purpose.
• Myalgia. Although there has been interest in using topical peppermint oil for myalgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Oral mucositis. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in adults undergoing stem cell transplantation shows that using an oral rinse containing peppermint oil and German chamomile three times daily, in addition to standard treatment with sodium chloride and chlorhexidine, reduces the duration and severity of mucositis and the use of narcotic analgesics when compared with placebo and standard treatment. However, this oral rinse does not reduce or delay the occurrence of mucositis or affect the duration of hospitalization (96363). Another small clinical study in adults with head and neck cancers undergoing radiation shows that rinsing with 5 mL of a polyherbal mouthwash containing peppermint oil, German chamomile, aloe vera, and honey for 1 minute 3 times daily for 6 weeks reduces oral mucositis incidence, severity, and pain when compared with chlorhexidine 0.2% and placebo (111291). Clinical research in adults receiving treatment with 5-fluorouracil shows that using an oral rinse containing peppermint, sage tea, and thyme in addition to basic oral care, starting on the first day of chemotherapy and continuing for 14 days, delays the onset of mucositis, but not the rate or severity of mucositis, when compared with basic oral care alone (96364). It is unclear if these effects are due to peppermint oil, other ingredients, or the combinations.
• Osteoarthritis. Although there has been interest in using topical peppermint oil for osteoarthritis, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Pain (acute). It is unclear if inhaled peppermint oil is beneficial for acute pain. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy reduces pain associated with intravenous catheterization by a small amount when compared with a distilled water control (102601).
• Postherpetic neuralgia. Although there has been interest in using topical peppermint oil for postherpetic neuralgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Postoperative ileus. It is unclear if oral peppermint oil is beneficial for the prevention of postoperative ileus. Details: Clinical research shows that taking a specific peppermint oil product (Colpermin, Tillotts Pharma) as two capsules three times daily for 5 days after routine gynecological surgery does not prevent postoperative abdominal distension and dyspepsia when compared with placebo (68602). Conversely, a small clinical study in patients undergoing elective cesarean section shows that taking 20 drops of peppermint oil 4 hours after surgery and then hourly for a total of three doses reduces the time to first bowel sounds by around 3.3 hours, first flatulence by 4.4 hours, and first stool by 5 hours when compared with placebo (110092).
• Postoperative nausea and vomiting (PONV). Some preliminary clinical studies suggest that inhaled peppermint may be beneficial for PONV. However, it is unclear if the benefit is due to aromatherapy or improved breathing patterns. Details: Some preliminary clinical research shows that using peppermint aromatherapy helps relieve postoperative nausea (3804,13415,68524,104219,104220). Inhaling peppermint oil 10% and 30% as aromatherapy reduces the severity of nausea when compared with placebo, with no significant difference between concentrations (104220). Small clinical trials show improvement in PONV within the first 4 hours after surgery. However, this effect diminishes beyond 4 hours (104219). Other preliminary clinical research shows that peppermint oil aromatherapy is no more effective for reducing postoperative nausea than inhaling isopropyl alcohol or saline (13416,68529). It is possible that any relief of postoperative nausea observed with peppermint aromatherapy results from improved breathing patterns after surgery rather than peppermint oil itself (13416,90512). One small study shows that inhaling peppermint oil while practicing controlled breathing does not appear to relieve PONV better than practicing controlled breathing alone (90512). Some preliminary clinical research shows that inhaling vapors from a mixture of peppermint, ginger, spearmint, and cardamom essential oils reduces symptoms of postoperative nausea in approximately 15% more patients when compared with inhaling ginger essential oils alone, and in approximately 43% more patients when compared with inhaling saline (89888). However, it is not clear if the effect is due to peppermint, the other oils, or the combination.
• Postoperative pain. It is unclear if inhaled peppermint oil is beneficial for postoperative pain. Details: Preliminary clinical research in adults undergoing open heart cardiac surgery shows that receiving aromatherapy with peppermint oil 10%, 0.1 mL, three times daily for 7 doses moderately improves pain scores when compared with placebo (112747). Other preliminary clinical research in adults undergoing lumbar discectomy surgery shows that receiving aromatherapy with peppermint oil 5 drops once postoperatively modestly improves pain scores and anxiety scores when compared with no intervention (112744).
• Postoperative sleep disturbance. It is unclear if inhaled peppermint oil is beneficial for postoperative sleep disturbance. Details: Preliminary clinical research in adults undergoing open heart cardiac surgery shows that receiving aromatherapy with peppermint oil 10%, 0.1 mL, three times daily for 7 doses modestly improves sleep scores when compared with placebo (112747).
• Pre-procedural anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety prior to a medical procedure. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy does not reduce anxiety associated with intravenous catheterization when compared with a distilled water control (102601).
• Pregnancy-induced nausea and vomiting. Inhaled peppermint oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that aromatherapy with a mixture of 5% lemon and 5% peppermint essential oils modestly reduces the intensity of nausea and vomiting on days 2-4, but not day 1, when compared with placebo aromatherapy. When nauseated, patients placed three drops of the essential oil mixture (Barij Essence Co.) onto a cotton ball held 3 cm from the nose. This action could be repeated after 5 minutes if needed (105121).
• Pruritus. Some preliminary clinical studies suggest that topical peppermint oil improves itching of various etiologies. Details: Preliminary clinical research in adults with renal, hepatic, or diabetic pruritus shows that topical application of peppermint oil 5% in petrolatum twice daily for 2 weeks improves symptoms of pruritus when compared with petrolatum alone (96361). Preliminary clinical research in patients with severe or intractable pruritus secondary to burn scars shows that applying a specific product (Chongqing No.1, CQ-01, MJ Medical Gel Systems Ltd.) containing peppermint oil 3.6%, menthol 1.4%, and methyl salicylate 2.5%, covered with gauze for 24 hours, reduces the severity of pruritus for up to 7 days after application when compared with hydrogel covered with gauze or with gauze alone (96362). Preliminary clinical research in females experiencing itchy skin due to intrahepatic cholestasis of pregnancy also shows that applying peppermint oil 0.5% in sesame oil twice daily for 2 weeks reduces pruritus severity approximately 1.8-fold when compared with sesame oil alone (89478).
• Small intestinal bacterial overgrowth (SIBO). Although there has been interest in using oral peppermint for SIBO, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Stress. It is unclear if inhaled peppermint oil is beneficial for stress. Details: Clinical research shows that peppermint aromatherapy decreases physical and perceived levels of stress when compared with baseline (68422,68517). A small clinical study in adults undergoing a virtual reality (VR) driving scenario to test road rage shows that exposure to peppermint oil (Pure Essential Oil of Peppermint, Tisserand Aromatherapy) 5 drops via fan diffuser improves aggressive driving behavior scores but does not seem to improve self-reported stress, aggression, alertness, happiness, or calmness when compared with controls that did not receive aromatherapy during the VR session (112017).
• Toothache. Although there has been interest in using topical peppermint oil for toothache, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Urticaria. Although there has been interest in using topical peppermint oil for urticaria, there is insufficient reliable information about the clinical effects of peppermint for this condition. More evidence is needed to rate peppermint for these uses.

(Read more about PEPPERMINT)

LIKELY SAFE ...when used orally in amounts commonly found in food. Anise and anise oil have Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when anise powder is used orally and appropriately in medicinal amounts. Anise powder has been used with apparent safety in clinical research at doses of up to 9 grams daily for up to 4 weeks (94944,94945). ...when anise oil is used orally and appropriately in medicinal amounts. Anise oil has been used with apparent safety in clinical research at doses of up to 600 mg daily for up to 4 weeks (94946,94947).

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in food. Anise and anise oil have Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of anise when used by children in medicinal amounts.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in food. Anise and anise oil have Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of anise when taken orally in medicinal amounts during pregnancy or breast-feeding.

(Read more about ANISE)

LIKELY SAFE ...when consumed in amounts commonly found in foods. Ceylon cinnamon has Generally Recognized As Safe (GRAS) status in the US for use as a spice or flavoring agent (4912).

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts. Ceylon cinnamon 0.5-3 grams daily has been safely used in studies lasting up to 6 months (4,12,97248,97250,99874). ...when used as a mouth rinse for up to 15 days (92071). There is insufficient reliable information available about the safety of Ceylon cinnamon when used orally in greater amounts or for longer periods. Ceylon cinnamon contains trace amounts of coumarin (108260). In very high doses, coumarin can cause hepatotoxicity (15302). However, since the amount of coumarin in Ceylon cinnamon is negligible, it is unlikely to cause toxic effects (89652,92072,92073).

PREGNANCY: LIKELY SAFE
when consumed in amounts commonly found in foods (4912).

PREGNANCY: LIKELY UNSAFE
when used orally in amounts greater than those found in foods. Fetal abnormalities have been reported in animals (4,12).

LACTATION: LIKELY SAFE
when consumed in amounts commonly found in foods (4912). There is insufficient reliable information available about the safety of Ceylon cinnamon in amounts greater than those found in foods.

(Read more about CEYLON CINNAMON)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Fennel has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when fennel essential oil or extract is used orally and appropriately, short-term. Twenty-five drops (about 1.25 mL) of fennel fruit extract standardized to fennel 2% essential oil has been safely used four times daily for 5 days (49422). Also, two 100 mg capsules each containing fennel 30% essential oil standardized to 71-90 mg of anethole has been safely used daily for 8 weeks (97498). Powdered fennel extract has been used with apparent safety at a dose of 800 mg daily for 2 weeks (104199). ...when creams containing fennel 2% to 5% are applied topically (49429,92509).

CHILDREN: POSSIBLY SAFE
when combination products containing fennel are used to treat colic in infants for up to one week. Studied products include up to 20 mL of a fennel seed oil emulsion; a specific product (ColiMil) containing fennel 164 mg, lemon balm 97 mg, and German chamomile 178 mg; and up to 450 mL of a specific tea (Calma-Bebi, Bonomelli) containing fennel, chamomile, vervain, licorice, and lemon balm (16735,19715,49428).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Observational research has found that regular use of fennel during pregnancy is associated with shortened gestation (100513).

LACTATION: POSSIBLY UNSAFE
when used orally. Case reports have linked consumption of an herbal tea containing extracts of fennel, licorice, anise, and goat's rue to neurotoxicity in two breast-feeding infants. The adverse effect was attributed to anethole, a constituent of fennel and anise (16744). However, levels of anethole were not measured in breastmilk, and the herbal tea was not tested for contaminants. Furthermore, other adverse effects related to use of fennel during lactation have not been reported. However, until more is known, avoid using.

(Read more about FENNEL)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Lavender has Generally Recognized as Safe (GRAS) status for food use in the US (4912).

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts (9792). In clinical research, a specific product containing lavender oil (Silexan, Dr Willmar Schwabe GmbH & Co. KG) has been used safely at doses of 80-160 mg daily for up to 10 weeks (58077,58080,58098,97257). Powdered dried lavender flowers 500 mg twice daily has also been used with apparent safety for up to 8 weeks (97256). ...when used topically and appropriately. Lavender oil has been used safely for up to 7 months in adults (5177,109858,109865). ...when the essential oil is inhaled as a part of aromatherapy. Clinical studies have used lavender oil aromatherapy with apparent safety for up to 12 weeks (7107,12213,16393,16394,95634,103062,103063,103065,103068).

CHILDREN: POSSIBLY SAFE
when the essential oil is inhaled as a part of aromatherapy. Clinical studies have used lavender oil aromatherapy with apparent safety in single doses for up to 2 minutes (109868).

CHILDREN: POSSIBLY UNSAFE
when applied topically in males. Anecdotal reports suggest that applying topical products containing lavender oil to prepubertal males may result in gynecomastia in some cases (15254,95643). Products with a higher concentration of lavender oil and more frequent applications might be more likely to result in gynecomastia.

PREGNANCY AND LACTATION:
Insufficient reliable evidence available. Preliminary clinical research shows that lavender essential oil can be inhaled during labor, with no apparent adverse outcomes in the infants (95633). Although this study suggests safety, high quality assessment of safety has not been conducted.

(Read more about LAVENDER)

LIKELY SAFE ...when marshmallow root and leaf are used in amounts commonly found in foods. Marshmallow root has Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

POSSIBLY SAFE ...when marshmallow root and leaf are used orally in medicinal amounts (4,12). ...when used topically (4,62020). There is insufficient reliable information available about the safety of marshmallow flower.

PREGNANCY AND LACTATION:
Insufficient reliable information available.

(Read more about MARSHMALLOW)

POSSIBLY SAFE ...when used orally and appropriately, short-term (12). Meadowsweet flower has been used with apparent safety at doses of 2.5-3.5 grams daily. Meadowsweet herb has been used with apparent safety at doses of 4-5 grams daily (12).

POSSIBLY UNSAFE ...when used in large amounts or for prolonged periods of time. Meadowsweet contains salicylates and high amounts of tannins (4).

PREGNANCY: LIKELY UNSAFE
when used orally. Some evidence suggests meadowsweet might stimulate uterine activity (4).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about MEADOWSWEET)

LIKELY SAFE ...when peppermint oil is used orally, topically, or rectally in medicinal doses. Peppermint oil has been safely used in multiple clinical trials (3801,3804,6190,6740,6741,10075,12009,13413,14467,17681)(17682,68522,96344,96360,96361,96362,96363,96364,96365,99493).

POSSIBLY SAFE ...when peppermint leaf is used orally and appropriately, short-term. There is some clinical research showing that peppermint leaf can be used safely for up to 8 weeks (12724,13413). The long-term safety of peppermint leaf in medicinal doses is unknown. ...when peppermint oil is used by inhalation as aromatherapy (7107). There is insufficient reliable information available about the safety of using intranasal peppermint oil.

CHILDREN: POSSIBLY SAFE
when used orally for medicinal purposes. Enteric-coated peppermint oil capsules have been used with apparent safety under medical supervision in children 8 years of age and older (4469).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (96361). There is insufficient information available about the safety of using peppermint in medicinal amounts during pregnancy or lactation; avoid using.

(Read more about PEPPERMINT)

ACETAMINOPHEN (Tylenol, others) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might decrease the levels and clinical effects of acetaminophen.  Details Animal research shows that taking anise oil with acetaminophen decreases peak plasma levels of acetaminophen but does not reduce overall bioavailability (94951). Whether this interaction will occur in humans is unclear.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, anise seed might increase the risk of hypoglycemia when taken with antidiabetes drugs.  Details A small clinical study shows that anise seed powder decreases fasting blood glucose levels by 36% when compared to baseline (94953).

CAFFEINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might decrease the efficacy of caffeine.  Details Animal research shows that taking anise oil with caffeine decreases the bioavailability of caffeine (94951). Whether this interaction will occur in humans is unclear.

CODEINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might increase the effects and adverse effects of codeine.  Details Animal research shows that anise oil increases the analgesic effects of codeine, possibly by inducing its phase I metabolism and increasing conversion to morphine (94950). Whether this interaction occurs in humans is unclear.

CONTRACEPTIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise might interfere with contraceptive drug therapy.  Details Some in vitro research suggests that anise has estrogenic effects (13506), while other in vitro research suggests that anise has antiestrogenic effects (12728).

DIAZEPAM (Valium) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might increase the effects and adverse effects of diazepam.  Details Animal research shows that taking anise oil with diazepam increases the motor impairment associated with diazepam, possibly by inhibiting its breakdown by cytochrome P450 3A4 (94950). Whether this interaction occurs in humans is unclear.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise might interfere with estrogen-based hormone replacement therapy.  Details Some in vitro research suggests that anise has estrogenic effects (13506), while other in vitro research suggests that anise has antiestrogenic effects (12728).

FLUOXETINE (Prozac) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might decrease the efficacy of fluoxetine.  Details Animal research shows that taking anise oil with fluoxetine reduces the antidepressant effects of fluoxetine, possibly by promoting its breakdown by cytochrome P450 2D6 (94950). Whether this interaction occurs in humans is unclear.

IMIPRAMINE (Tofranil) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might decrease the efficacy of imipramine.  Details Animal research shows that taking anise oil with imipramine reduces the antidepressant effects of imipramine, possibly by promoting its breakdown by cytochrome P450 2D6 (94950). Whether this interaction occurs in humans is unclear.

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise oil might increase the effects and adverse effects of midazolam.  Details Animal research shows that taking anise oil with midazolam increases the motor impairment associated with midazolam, possibly by inhibiting its breakdown by cytochrome P450 3A4 (94950). Whether this interaction occurs in humans is unclear.

TAMOXIFEN (Nolvadex) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, anise might interfere with tamoxifen therapy.  Details Some in vitro research suggests that anise has estrogenic effects (13506), while other in vitro research suggests that anise has antiestrogenic effects (12728).

(Read more about ANISE)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Ceylon cinnamon may have additive effects with antidiabetes drugs.  Details Ceylon cinnamon may lower blood glucose levels (11247,11248,11973). Dose adjustments might be necessary.

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Ceylon cinnamon might have additive effects with antihypertensive drugs and increase the risk of hypotension.  Details Animal research shows that Ceylon cinnamon extract has vasorelaxant properties and reduces blood pressure in rat models of hypertension, possibly via inhibition of calcium influx through L-type voltage-sensitive channels (92085,92086).

(Read more about CEYLON CINNAMON)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fennel might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.  Details Animal research suggests that fennel oil has antithrombotic and antiplatelet effects (31415,49445).

CIPROFLOXACIN (Cipro) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, fennel might decrease the levels and clinical effects of ciprofloxacin.  Details Animal research shows that fennel reduces ciprofloxacin bioavailability by nearly 50%, possibly due to the metal cations such as calcium, iron, and magnesium contained in fennel. This study also found that fennel increased tissue distribution and slowed elimination of ciprofloxacin (6135).

CONTRACEPTIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might decrease the effects of contraceptive drugs due to competition for estrogen receptors.  Details Some constituents of fennel have estrogenic activity (11).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fennel might increase levels of drugs metabolized by CYP3A4.  Details In vitro research suggests that fennel inhibits CYP3A4 enzyme activity (38375,49468). This effect has not been reported in humans.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might interfere with hormone replacement therapy due to competition for estrogen receptors.  Details Some constituents of fennel have estrogenic activity (11).

TAMOXIFEN (Nolvadex) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might decrease the antiestrogenic effect of tamoxifen.  Details Some constituents of fennel have estrogenic activity (11), which may interfere with the antiestrogenic activity of tamoxifen.

(Read more about FENNEL)

CNS DEPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, lavender might potentiate the therapeutic effects and adverse effects of CNS depressants.  Details Laboratory research suggests that lavender has sedative effects (7). However, clinical studies in patients taking oral lavender oil (Silexan) 160 mg for 10 weeks or taking lavender flower powder 1 gram daily for 2 months have not reported side effects of drowsiness, sedation, or sleepiness (97256,103061). There is still some concern that higher doses or different preparations of lavender might have additive effects with CNS depressant medications.

(Read more about LAVENDER)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, marshmallow flower might have antiplatelet effects.  Details Animal research suggests that marshmallow flower extract has antiplatelet effects (92846). However, the root and leaf of marshmallow, not the flower, are the plant parts most commonly found in dietary supplements. Theoretically, use of marshmallow flower with anticoagulant/antiplatelet drugs can have additive effects, and might increase the risk for bleeding in some patients.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, due to potential diuretic effects, marshmallow might reduce excretion and increase levels of lithium.  Details Marshmallow is thought to have diuretic properties. To avoid lithium toxicity, the dose of lithium might need to be decreased when used with marshmallow.

ORAL DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, mucilage in marshmallow might impair absorption of oral drugs.  Details Marshmallow contains mucilage which can affect oral drug absorption (1,11,12,19). To avoid changes in absorption, take marshmallow 30-60 minutes after oral medications.

(Read more about MARSHMALLOW)

ASPIRIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, meadowsweet might have an additive effect with other salicylate-containing drugs, such as aspirin.  Details Meadowsweet contains salicin, a plant salicylate; however, salicin doesn't seem to have the antiplatelet effects of aspirin (12).

CHOLINE MAGNESIUM TRISALICYLATE (Trilisate) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, meadowsweet might have an additive effect with other salicylate-containing drugs, such as choline magnesium trisalicylate (12).  Details Meadowsweet contains salicin, a plant salicylate (12).

SALSALATE (Disalcid) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, meadowsweet might have an additive effect with other salicylate-containing drugs such as salsalate (12).  Details Meadowsweet contains salicin, a plant salicylate (12).

(Read more about MEADOWSWEET)

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint oil might increase the levels and adverse effects of cyclosporine.  Details In animal research, peppermint oil inhibits cyclosporine metabolism and increases cyclosporine levels. Inhibition of cytochrome P450 3A4 (CYP3A4) may be partially responsible for this interaction (11784). An interaction between peppermint oil and cyclosporine has not been reported in humans.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, peppermint might increase the levels of CYP1A2 substrates.  Details In vitro and animal research shows that peppermint oil and peppermint leaf inhibit CYP1A2 (12479,12734). However, in clinical research, peppermint tea did not significantly affect the metabolism of caffeine, a CYP1A2 substrate. It is possible that the 6-day duration of treatment may have been too short to identify a difference (96359).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint might increase the levels of CYP2C19 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C19 (12479). So far, this interaction has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint might increase the levels of CYP2C9 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C9 (12479). So far, this interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, peppermint might increase the levels of CYP3A4 substrates.  Details Clinical research in healthy volunteers shows that a single dose of peppermint oil 600 mg inhibits CYP3A4 enzymes and increases the AUC of felodipine, a CYP3A4 substrate (11783). However, in vitro research suggests that peppermint oil only inhibits CYP3A4 at very high concentrations (12479).

(Read more about PEPPERMINT)

General ...Orally, anise seems to be well tolerated.
Most Common Adverse Effects:
Topically: Contact dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis in sensitive individuals.

Dermatologic ...Topically, anise, in combination with other herbs, has been reported to cause localized pruritus (13483).

Immunologic ...Anise can cause allergic reactions in sensitive individuals. Orally or by inhalation, anise can cause rhinoconjunctivitis, occupational asthma, and anaphylaxis (13484). Topically, anise can cause contact dermatitis, rhinitis, and asthma (31319,31341). Contact dermatitis and cheilitis have also been reported following the use of toothpaste containing anethole, a constituent of anise (31403,31528).

(Read more about ANISE)

General ...Orally, Ceylon cinnamon is generally well tolerated, and adverse reactions are uncommon.
Most Common Adverse Effects:
Orally: Bloating, dyspepsia, nausea.
Topically: Allergic dermatitis, irritation of mucous membranes and skin.

Dermatologic ...Orally, a case of systemic contact dermatitis has been reported in a patient who consumed cinnamon (type not specified) after being previously sensitized to cinnamyl alcohol via cutaneous exposure (95599). In a small study of oral Ceylon cinnamon, two patients reported itching (104520). In another small study, two patients reported rashes (108263).
Topically, cinnamon oil can cause skin irritation and allergic dermatitis, probably due to cinnamaldehyde which makes up 60% to 80% of cinnamon oil (2537,12635,92071,95596,95599). In one case report, a 16-year-old female experienced worsening dermatitis after using a homemade facial scrub containing cinnamon powder (type not specified). Symptoms improved after discontinuation of the scrub (95596). Several cases of intraoral allergic contact dermatitis have been reported in patients consuming cinnamon (type not specified) or using products containing constituents of cinnamon (95598).

Gastrointestinal ...Orally, gastrointestinal side effects such as heartburn, nausea, bloating, and dyspepsia have been reported (97250).

Hematologic ...Orally, a case of postoperative hemorrhage is reported in a 49-year-old patient after taking Ceylon cinnamon 1 tablespoon daily for 10 months. One day post-colectomy, the patient had an INR of 1.59 and intraabdominal bleeding that required exploratory laparotomies, blood transfusion, and fresh frozen plasma. Ultimately, the patient was discharged (112421).

Hepatic ...While there is concern about the coumarin content in cassia cinnamon increasing the risk for hepatic adverse effects and bleeding, the amount of coumarin in Ceylon cinnamon is negligible and unlikely to cause toxic effects (89652,92072,92073). In one case report, a 73-year-old female taking rosuvastatin for several months developed elevated liver function tests (LFTs), abdominal pain, nausea, and vomiting after taking cinnamon (unknown dose and type) for 7 days. The acute hepatitis and elevated LFTs resolved after stopping both cinnamon and rosuvastatin. The patient was later able to resume rosuvastatin without recurrence (97249).

(Read more about CEYLON CINNAMON)

General ...Orally and topically, fennel seems to be well tolerated.
Most Common Adverse Effects:
Orally: Gastrointestinal discomfort, photosensitivity, and allergic reactions in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Seizures.

Dermatologic ...Advise patients to avoid excessive sunlight or ultraviolet light exposure while using fennel (19). Allergic reactions affecting the skin such as atopic dermatitis and photosensitivity may occur in patients who consume fennel (6178,49507).

Gastrointestinal ...Orally, fennel may cause gastrointestinal complaints, including nausea and vomiting (19146,104196).

Hematologic ...Methemoglobinemia has been reported in four infants following intoxication related to ingestion of a homemade fennel puree that may have been made from improperly stored fennel (49444).

Immunologic ...A case report describes an 11-year-old male who developed an allergy to fennel-containing toothpaste. Immediately after using the toothpaste, the patient experienced sneezing, coughing, itchy mouth, rhinorrhea, nasal congestion, wheezing, difficulty breathing, and palpitations, which resolved within 10 minutes of spitting out the toothpaste and rinsing the mouth. In challenge tests, the patient reacted to chewing fresh fennel root, but not ground fennel seeds (103822).

Neurologic/CNS ...Orally, fennel oil has been associated with tonic clonic and generalized seizures (12868). New-onset cluster headaches are reported in a 24-year-old female while using a toothpaste containing fennel and camphor for 3 months. The headaches resolved upon stopping the toothpaste (112368). It is unclear if this adverse effect can be attributed to fennel, camphor, or the combination.

Pulmonary/Respiratory ...Orally, fennel and fennel seed have been reported to cause bronchial asthma (49478).

(Read more about FENNEL)

General ...Orally, lavender is well tolerated in food amounts and seems to be well tolerated in larger amounts. Topically, lavender oil seems to be well tolerated.
Most Common Adverse Effects:
Orally: Breath odor, constipation, diarrhea, dyspepsia, eructation, headache, and nausea.
Topically: Allergic contact dermatitis (with lavender oil).
Serious Adverse Effects (Rare):
Topically: Cases of gynecomastia have been reported in prepubertal males using lavender oil.

Cardiovascular ...Orally, a specific lavender oil ingredient (Silexan) has been associated with palpitations (103061).

Endocrine ...Topical products containing lavender oil alone, including a product referred to as agua de violetas, or in combination with tea tree oil have been linked to at least six cases of gynecomastia when used in prepubertal males. In each case, gynecomastia resolved when the lavender oil products were discontinued. It is thought that the estrogenic and antiandrogenic activity of lavender oil and tea tree oil resulted in gynecomastia in these cases (15254,95643).

Gastrointestinal ...Orally, lavender oil, including a specific lavender oil ingredient KG), may cause gastrointestinal disturbance, including dyspepsia, diarrhea, breath odor, eructation, and nausea (58077,58080,58098,93004,103061). Tincture of lavender has been linked to cases of constipation and increased appetite; however, it is unknown if this occurred at a greater rate than with placebo (9792).

Immunologic ...Topically, use of lavender oil, such as in personal care products, might cause allergic contact dermatitis in some patients (6,101728). There have been numerous case reports of allergic contact dermatitis and eczema linked to lavender oil exposure from shampoos, lotions, fragrances, or direct application of oil to pillows (10031,58043,58109,58120,101728).

Neurologic/CNS ...Orally, lavender flower powder, tincture of lavender containing 50% alcohol, and a specific lavender oil ingredient (Silexan) have been linked to headache (9792,103061,109860). Headache has also been reported rarely following lavender oil aromatherapy (109860).

Pulmonary/Respiratory ...In one case report, a 34-year-old Japanese female presented with complaints of dyspnea, cough, and fever 2 weeks after initiating lavender essential oil therapy via humidifier. The patient had an oxygen saturation of 88% and was diagnosed with acute eosinophilic pneumonia. Symptoms improved after a course of corticosteroids and discontinuation of aromatherapy (109979).

(Read more about LAVENDER)

General ...Orally and topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.

(Read more about MARSHMALLOW)

General ...Orally, meadowsweet seems to be well tolerated.

Dermatologic ...Meadowsweet contains salicylate constituents. There is insufficient reliable information available to know if the side effects and toxicity normally associated with salicylates could occur with meadowsweet use. Orally, adverse reactions associated with salicin include skin rashes (4).

Gastrointestinal ...Orally, large doses of meadowsweet can cause nausea and other stomach complaints (18).
Meadowsweet contains salicylate constituents. There is insufficient reliable information available to know if the side effects and toxicity normally associated with salicylates could occur with meadowsweet use. Adverse reactions associated with salicylates include gastric irritation, hematochezia, nausea, and vomiting (4).

Immunologic ...Meadowsweet contains salicylate constituents. There is insufficient reliable information available to know if the side effects and toxicity normally associated with salicylates could occur with meadowsweet use. Orally, salicylates can cause hypersensitivity in sensitive individuals (4).

Ocular/Otic ...Meadowsweet contains salicylate constituents. There is insufficient reliable information available to know if the side effects and toxicity normally associated with salicylates could occur with meadowsweet use. Orally, adverse reactions with salicylates include tinnitus (4).

Pulmonary/Respiratory ...Orally, large doses of meadowsweet can cause bronchospastic activity (4).

Renal ...Meadowsweet contains salicylate constituents. There is insufficient reliable information available to know if the side effects and toxicity normally associated with salicylates could occur with the use of meadowsweet. Orally, adverse reactions with salicylates include renal irritation (4).

(Read more about MEADOWSWEET)

General ...Orally, topically, or rectally, peppermint oil is generally well tolerated. Inhaled, peppermint oil seems to be well tolerated. Intranasally, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted. Orally, peppermint leaf seems to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, anal burning, belching, diarrhea, dry mouth, heartburn, nausea, and vomiting.
Topically: Burning, dermatitis, irritation, and redness.

Dermatologic ...Topically, peppermint oil can cause skin irritation, burning, erythema, and contact dermatitis (3802,11781,31528,43338,68473,68457,68509,96361,96362). Also, a case of severe mucosal injury has been reported for a patient who misused an undiluted over the counter mouthwash that contained peppermint and arnica oil in 70% alcohol (19106).
In large amounts, peppermint oil may cause chemical burns when used topically or orally. A case of multiple burns in the oral cavity and pharynx, along with edema of the lips, tongue, uvula, and soft palate, has been reported for a 49-year-old female who ingested 40 drops of pure peppermint oil. Following treatment with intravenous steroids and antibiotics, the patient's symptoms resolved over the course of 2 weeks (68432). Also, a case of chemical burns on the skin and skin necrosis has been reported for a 35-year-old male who spilled undiluted peppermint oil on a previous skin graft (68572). Oral peppermint oil has also been associated with burning mouth syndrome and chronic mouth ulceration in people with contact sensitivity to peppermint (6743). Also, excessive consumption of mint candies containing peppermint oil has been linked to cases of stomatitis (13114).

Gastrointestinal ...Orally, peppermint oil can cause heartburn, nausea and vomiting, anal or perianal burning, abdominal pain, belching, dry mouth, diarrhea, and increased appetite (3803,6740,6741,6742,10075,11779,11789,17682,68497,68514)(68532,68544,96344,96360,102602,104219,107955). Enteric-coated capsules might help to reduce the incidence of heartburn (3802,4469,6740,11777). However, in one clinical study, a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) taken as 180 mg three times daily was associated with a higher rate of adverse effects when compared with placebo (48% versus 31%, respectively). Specifically, of the patients consuming this product, 11% experienced belching and 26% experienced heartburn, compared to 2% and 12%, respectively, in the placebo group (107955). A meta-analysis of eight small clinical studies in patients with irritable bowel syndrome shows that taking enteric-coated formulations of peppermint oil increases the risk of gastroesophageal reflux symptoms by 67% when compared with a control group (109980). Enteric-coated capsules can also cause anal burning in people with reduced bowel transit time (11782,11789).

Genitourinary ...Orally, a sensitive urethra has been reported rarely (102602).

Hepatic ...One case of hepatocellular liver injury has been reported following the oral use of peppermint. Symptoms included elevated liver enzymes, fatigue, jaundice, dark urine, and signs of hypersensitivity. Details on the dosage and type of peppermint consumed were unavailable (96358).

Immunologic ...One case of IgE-mediated anaphylaxis, characterized by sudden onset of lip and tongue swelling, tightness of throat, and shortness of breath, has been reported in a 69-year-old male who consumed peppermint candy (89479). An allergic reaction after use of peppermint oil in combination with caraway oil has been reported in a patient with a history of bronchial asthma (96344). It is not clear if this reaction occurred in response to the peppermint or caraway components.

Neurologic/CNS ...Orally, headache has been reported rarely (102602).

Ocular/Otic ...Orally, peppermint has been reported to cause blurry vision (3803).

(Read more about PEPPERMINT)