Chuan Xiong Cha Tiao Wan by Lanzhou Foci Herb Factory

There is insufficient reliable information available about the effectiveness of asarabacca.

(Read more about ASARABACCA)

POSSIBLY EFFECTIVE

• Atopic dermatitis (eczema). Some clinical research suggests that topical licorice seems to improve symptoms of atopic dermatitis. Details: Applying gel formulations containing 1% or 2% licorice root extract three times daily for 2 weeks seems to reduce erythema by 35% to 61%, edema by 57% to 84%, and itching by 44% to 73%. The 2% gel seems to be more effective than the 1% gel (59732).
• Canker sores. Some clinical research suggests that topical licorice patches and mouth rinses seems to reduce ulcer size and pain in patients with recurrent aphthous stomatitis. Details: Clinical research shows that applying an oral patch containing licorice 0.015-0.229 mg/kg for 16 hours each day for 8 days does not affect ulcer healing time, but reduces ulcer size and post-stimulus pain, when compared with placebo (59769). A small clinical study also shows that applying bioadhesive hydrogel patches containing 1% licorice extract reduces the pain, as well as the diameter of necrosis and inflammatory halo of recurrent canker sores, when compared to baseline (59781). Mouth rinses containing licorice have also been used. One clinical study shows that swishing a diphenhydramine and 5% licorice extract solution around the mouth for about 3 minutes four times daily until the sores have healed reduces the average time to healing by 1.5 days when compared to a solution containing diphenhydramine alone. Pain was reduced by up to 69% more in those using licorice extract (104564). Another small clinical study shows that gargling with licorice extract four times daily for 2 days has a large beneficial effect on pain and ulcer size when compared with using a placebo gargle. The licorice extract was made by boiling licorice root 40 grams in one liter of water for 30 minutes and cooled (110319). In addition, preliminary clinical research shows that gargling with warm water containing deglycyrrhizinated licorice powder 200 mg four times daily for 7 days improves pain in 75% of patients by day one and results in complete healing in 75% of patients by day three (59857).
• Endotracheal intubation-related adverse effects. Some clinical research suggests that using licorice as a gargle or lozenge prior to endotracheal intubation can reduce adverse effects like sore throat and cough. Details: A meta-analysis of 5 clinical trials in patients undergoing elective surgical procedures shows that topical use of licorice, either as a gargle or lozenge, prior to endotracheal intubation reduces the risk for sore throat by 56% and reduces the risk for cough by 39% when compared with a control group at 24 hours post-extubation (100985). One clinical study included in this analysis shows that sucking on a single lozenge (Sualin, Hamdard Pharma) containing licorice extract 97 mg beginning 30 minutes prior to intubation reduces the risk for cough immediately after extubation by 56% when compared with a sugar candy lozenge. However, it doesn't seem to reduce cough at 30 minutes, 12 hours, or 24 hours post-extubation. This lozenge also appears to reduce the risk for sore throat by about 32% at 12 and 24 hours post-extubation, but not immediately or 30 minutes after extubation (25670). Additional clinical studies included in the meta-analysis show that gargling with fluid prepared with licorice 0.5 grams for at least one minute beginning 5 minutes prior to endotracheal intubation reduces the incidence and severity of post-extubation sore throat and coughing when compared with a water control (26464,59793).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Topical licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with mild to moderate acne associated with mask wearing shows that topical application of a combination of licorice root extract 0.3%, calendula 4%, and snail secretion filtrate 40% (AI complex) to the face twice daily for 12 weeks modestly reduces inflammatory, but not non-inflammatory or total, acne lesions when compared with placebo. There was no difference in overall treatment success, defined as at least almost clear skin or a large improvement (110322). It is unclear if any benefits are due to licorice, other ingredients, or the combination.
• Addison disease. Although there has been interest in using oral licorice for Addison disease, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Adrenal insufficiency. Although there has been interest in using oral licorice for adrenal insufficiency, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Allergic rhinitis (hay fever). It is unclear if using a licorice-containing nasal irrigation suspension improves symptoms in patients with allergic rhinitis. Details: A clinical study in patients with allergic rhinitis shows that using a nasal irrigation suspension containing licorice extract 900 mg daily for 1 month improves symptoms such as nasal blockage, rhinorrhea, sneezing, postnasal discharge, and olfactory disturbance when compared with baseline (108569). Although the study also utilized mometasone 2 mg nasal spray and isotonic saline nasal irrigation as comparators, symptom improvement was observed in all three groups, and there was no statistical comparison of outcomes between groups.
• Antipsychotic-induced hyperprolactinemia. Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in females with risperidone-induced hyperprolactinemia shows that taking a combination of licorice and peony (Peony-Glycyrrhiza Decoction; PGD) 45 grams daily for 4 weeks reduces prolactin levels to a similar extent as bromocriptine (59775). However, another study shows that taking the same product at the same dose for 16 weeks has no effect on prolactin levels in females with antipsychotic-induced hyperprolactinemia when compared with placebo. Although the prolactin-related adverse event questionnaire total score was moderately improved, there was no effect on clinically meaningful symptoms or menstrual resumption (97219). Both studies show no effect on psychotic symptoms (59775,97219). Preliminary clinical research in male patients with antipsychotic-induced hyperprolactinemia shows that taking an herbal extract containing licorice and peony (shakuyaku-kanzo-to) 2.5 grams three times daily reduces prolactin levels after 4 weeks, but does not have a significant effect on prolactin levels 4 weeks after treatment cessation (59907).
• Bleeding. Topical licorice might reduce bleeding when used in combination with other ingredients; its effect when used alone is unclear. Details: Some preliminary clinical research shows that topically applying 4 mL of a specific product (Ankaferd Blood Stopper, Mefar Ilaç Sanayi A.S.) containing licorice, Alpinia, thyme, stinging nettle, and common grape vine reduces bleeding, but does not improve the surgical time for episiotomy repair, when compared with saline (31010). Other preliminary clinical research shows that ampules of this same product placed in empty alveolus for up to 20 minutes reduces bleeding in postsurgical dental patients with increased bleeding tendency (31002).
• Cancer-related pain. It is unclear if oral licorice is beneficial for pain in patients with cancer. Details: Preliminary clinical research shows that taking a 1:1 combination of licorice root and peony root, along with a Taiwanese tonic vegetable soup comprised of lily bulb, lotus seed, and jujube fruit, reduces pain levels in terminal cancer patients when compared with patients consuming only the soup or the regular hospital diet (59770).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral licorice for CFS, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Colic. Although there has been interest in using oral licorice for colic, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Coronavirus disease 2019 (COVID-19). Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients hospitalized in Egypt with moderate COVID-19 shows that administering oral licorice extract 300 mg (standardized to contain glycyrrhizin 60 mg) once daily and Boswellia serrata extract 300 mg twice daily for 14 days, along with following an institution-based COVID-19 treatment protocol, may modestly improve mortality and time to recovery when compared with patients receiving the standard protocol alone. The standard treatment protocol included acetaminophen, azithromycin, vitamin C, zinc, and enoxaparin (108579). It is unclear if any effect is due to licorice, Boswellia serrata, or the combination.
• Dental caries. It is unclear if oral licorice is beneficial for the prevention of dental caries. Details: One clinical study in adults shows that swishing 15 mL of a solution containing licorice extract 1% once nightly before bed for 5 days may reduce the acid production of cavity-causing bacteria, which may modestly reduce cavity risk, when compared with using a saline solution (108567). The validity of this study is limited by the short duration of treatment and follow-up.
• Dental plaque. It is unclear if licorice toothpaste or mouthwash is beneficial for reducing plaque. Details: Preliminary clinical research shows that using 0.25% or 0.50% glycyrrhizin-containing toothpaste twice daily does not reduce the amount of plaque, gingivitis, or bleeding in patients with proper dental hygienic measures when compared with the same toothpaste without glycyrrhizin (59812). Also, other preliminary clinical research shows that using glycyrrhizin-containing mouthwash for 3 days does not significantly reduce plaque levels (59855).
• Depression. It is unclear if adding oral licorice to standard treatment is beneficial for improving depression. Details: A very small, nonblinded clinical study in hospitalized adults with major depressive disorder shows that adding licorice extract 1400 mg daily, standardized to glycyrrhizin 7% to 8%, to standard treatment for 2 weeks improves depression rating scores when compared with baseline, although these improvements were numerically similar to those seen with standard treatment alone. Patients in the treatment group also took oral magnesium citrate 300 mg daily to prevent magnesium depletion. The validity of this finding is limited due to the small size of the study, short duration of treatment, and unclear reporting (108575).
• Diabetes. Although there has been interest in using oral licorice for diabetes, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Dry mouth. It is unclear if rinsing the mouth with licorice is beneficial for dry mouth in people on hemodialysis. Details: Preliminary clinical research in hemodialysis patients with dry mouth shows that rinsing with a licorice mouthwash containing 8.34 grams of licorice concentrate per 500 mL of water with every meal for 10 days does not affect salivary flow rate, but reduces subjective feelings of dry mouth by about 28%, when compared with a water-based mouthwash and control group (97220).
• Dysmenorrhea. It is unclear if oral licorice is beneficial for reducing pain. Details: Preliminary clinical research shows that taking a syrup providing licorice extract 750 mg twice daily for the first 5 days of the menstrual cycle reduces pain as effectively as ibuprofen 400 mg every 8 hours in patients with moderate or severe dysmenorrhea (104558).
• Dyspepsia. Oral licorice might improve symptoms of dyspepsia when used in combination with other ingredients; its effect when used alone is unclear. Details: Various combination products manufactured by Steigerwald Arzneimittelwerk GmbH have been evaluated for dyspepsia. Two specific combination products containing licorice root (Iberogast; STW-5-S) seem to improve symptoms of dyspepsia. The combinations include licorice plus milk thistle, peppermint leaf, German chamomile, caraway, celandine, angelica, and lemon balm either with (Iberogast) or without clown's mustard plant (STW-5-S) 1 mL three times daily for 4 weeks (19532). A meta-analysis of studies using the Iberogast product shows that taking 1 mL orally three times daily over a period of 4 weeks reduces severity of acid reflux, epigastric pain, cramping, nausea, and vomiting when compared with placebo (13089). Also, using a preparation containing clown's mustard plant, German chamomile, peppermint, caraway, licorice, and lemon balm (STW 5-II) 1 mL three times daily for up to 12 weeks improves dyspepsia symptoms in 40% more patients when compared with placebo (12724).
• Familial Mediterranean fever. It is unclear if oral licorice is beneficial for familial Mediterranean fever. Details: Preliminary clinical research shows that taking a combination of licorice, andrographis, Siberian ginseng, and schisandra (ImmunoGuard, Inspired Nutritionals) four tablets three times daily for one month reduces the duration, frequency, and severity of attacks of familial Mediterranean fever in children when compared with placebo (12382). It is unclear if these effects are due to licorice, other ingredients, or the combination.
• Helicobacter pylori. It is unclear if oral licorice is beneficial for Helicobacter pylori eradication. Details: Some preliminary clinical research shows that adding licorice (D-Reglis, Iran Darouk Pharmaceutical Co.) 380 mg twice daily to conventional clarithromycin-based triple therapy for 14 days improves eradication rate by an additional 21% when compared with conventional treatment alone. However, any additional benefit might be limited to patients with peptic ulcer disease (97221). Other preliminary clinical research shows that taking a combination of licorice extract 100 mg and Lactobacillus paracasei HP7 in 150 mL of fermented milk daily for 8 weeks does not increase eradication rates when compared with fermented milk alone, although it may improve gastrointestinal symptom scores, decrease the gastric load of Helicobacter pylori, and improve some measures of inflammation when compared to baseline (100984).
• Hepatitis. Evidence for the use of intravenous licorice in the management of hepatitis B and C is mixed. Details: In some preliminary clinical research, a specific glycyrrhizin-containing intravenous preparation (Stronger Neominophagen C, Minophagen Pharmaceutical Co. Ltd.) appears to reduce mortality due to viral hepatitis by about 50% (3250). Other clinical research suggests that this same product reduces serum alanine aminotransferase (ALT) in hepatitis C patients but does not improve hepatitis C virus (HCV)-RNA levels (3247,59712,59721,59920). When used long-term, this preparation seems to reduce the risk of hepatocellular carcinoma in hepatitis C patients when compared to long-term use of other supplements, such as vitamin K (59905). This product has been used in various doses: 40 or 100 mL, containing 2 mg glycyrrhizin, 1 mg cysteine, and 20 mg of glycine per mL of solution, administered daily for 4-8 weeks, followed by 40 or 100 mL 2-7 times weekly for 2-16 weeks, has been used (3250,59905,59915); 40-120 mL diluted in 100 mL of 5% glucose solution and administered three times weekly for 4 weeks (59712,59721); 100 mL, which contained 200 mg glycyrrhizin, administered undiluted six times weekly for 4 weeks (59721); or 60 mL administered three times weekly for 16 weeks (59920). Other research shows that this preparation reduces ALT, aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT) in patients with hepatitis B virus (59915). Oral licorice has not been evaluated for this purpose.
• Hypercholesterolemia. It is unclear if oral licorice is beneficial for improving cholesterol. Details: Preliminary clinical research shows that taking licorice root extract 0.1 grams daily for one month reduces plasma total cholesterol levels by 5%, plasma low-density lipoprotein (LDL) cholesterol levels by 9%, and plasma triglyceride levels by 14% when compared with baseline in patients with moderate hypercholesterolemia (59725). The validity of these findings is limited by the lack of a comparator group.
• Hyperkalemia. It is unclear if oral licorice is beneficial for reducing potassium levels. Details: Some clinical research in adults with diabetes and hypoaldosteronism suggests that taking glycyrrhizin 150 mg daily decreases potassium levels when compared with calcium polystyrene sulfonate (59897). Also, one very small clinical study in patients with anuria shows that taking glycyrrhetinic acid 1 gram daily for 2 weeks seems to decrease plasma potassium, but does not improve blood pressure, when compared with placebo (59723).
• IgA vasculitis. Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small retrospective study in patients aged 5-36 years with newly diagnosed IgA vasculitis shows that taking compound glycyrrhizin (Eisai Pharmaceutical Co, Ltd) three times daily along with loratadine, calcium, vitamin C, rutin, and other unspecified conventional treatments is associated with an improvement in cutaneous purpura symptoms and time to symptom regression when compared with placebo. After 1 month, the rate of complete resolution and time to regression in the treatment group was 82% and 5 days, respectively, compared with 65% and 8 days, respectively, in the placebo group. Compound glycyrrhizin contained glycyrrhizin, glycine, and methionine and was dosed by age, with a dose of 25 mg daily in those 12 years or younger and 50 mg daily in those over 12 years (108580).
• Irritable bowel syndrome (IBS). Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that a formulation containing licorice root, slippery elm bark, lactulose, and oat bran daily for 2 weeks improves stool consistency and increases bowel movement frequency by 20% in individuals with constipation-predominant IBS when compared to baseline. Symptoms of abdominal pain, bloating, straining, and global severity might also be reduced (35462). The validity of these findings is limited by the lack of a comparator group. Additionally, it is unclear if any benefits are due to licorice, other ingredients, or the combination.
• Lichen planus. It is unclear if intravenous licorice is beneficial for lichen planus. Details: A very small clinical study shows that intravenous administration of 0.2% glycyrrhizin solution, 40 mL daily for 4 weeks, improves clinical symptoms of oral lichen planus in a greater percentage of patients with chronic hepatitis C when compared with dental cleaning (59903). There is no evidence suggesting that oral licorice is beneficial.
• Liver cancer. Although there has been interest in using oral or intravenous licorice preparations for liver cancer, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Melasma. Topical licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that applying a topical cream (Clariderm Clear, Stiefel Laboratories Inc.) containing 7% licorice, emblica, and belides twice daily for 60 days is as effective as a cream containing 2% hydroquinone for lightening the skin in patients with melasma (59824). It is unclear if this effect is due to licorice, other ingredients, or the combination.
• Menopausal symptoms. It is unclear if oral licorice is beneficial for reducing hot flash frequency or severity. Details: In one preliminary clinical study, taking licorice root extract 330 mg orally three times daily for 8 weeks modestly reduces the frequency of hot flashes by about 1.3 per day and the severity of hot flashes by about 40% when compared with placebo (94659). However, another preliminary clinical study shows that taking a specific licorice root extract (D-Reglis, Iran Darouk Pharmaceutical Co.) 650 mg orally daily for 90 days does not reduce the number or severity of hot flashes when compared to baseline (25694).
• Muscle cramps. It is unclear if oral licorice is beneficial for muscle cramps due to cirrhosis or hemodialysis. Details: Preliminary clinical research shows that taking a specific combination of licorice and peony (shakuyaku-kanzo-to) might reduce muscle cramps in patients with hepatic cirrhosis or in patients undergoing hemodialysis when compared to baseline (13550,13551,13552). This combination was taken as 6-7.5 grams daily in up to three divided doses for 2-4 weeks in two studies (13550,13552). In a third study, the combination was taken as 2.5 grams during hemodialysis with self-administration at the onset of muscle cramping (13551).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral licorice is beneficial for NAFLD. Details: A small clinical trial in females with NAFLD shows that taking licorice extract (Shirin Darou Company, Shiraz, Iran) 500 mg twice daily for 12 weeks improves some measures of liver health and glycemic control when compared with placebo. Modest improvements occurred in levels of alanine aminotransferase, as well as in measures of insulin resistance and severity of liver steatosis based on ultrasonographic evaluation. There were no effects on body mass index (BMI), plasma lipids, fasting blood glucose, or other liver enzymes. All patients were also given weight loss and healthy lifestyle advice (110320). Preliminary clinical research shows that taking licorice root extract 2 grams daily for 2 months reduces liver function enzyme levels in patients with NAFLD when compared to pre-treatment (59841). It is unclear if this reduction is clinically significant.
• Obesity. It is unclear if oral licorice is beneficial for weight loss. Details: Preliminary clinical research shows that taking a specific licorice flavonoid oil (Glavonoid) 300 mg daily for 8 weeks has no effect on weight or body fat when compared with placebo in obese patients (17727).
• Oral mucositis. It is unclear if oral or topical licorice is beneficial for the prevention or treatment of chemotherapy- or radiation-induced oral mucositis. Details: In patients with head and neck cancer undergoing chemoradiation, preliminary clinical research shows that using oral and topical licorice powder twice daily in addition to conventional treatments for 6 weeks reduces the overall incidence of mucositis and also reduces the risk of developing severe oral mucositis to 15.5%, compared with 20% in those using topical honey and 43% in those using conventional treatments alone. Licorice treatment consisted of yastimadhu powder 5 grams mixed in honey for topical application in the mouth, as well as yastimadhu capsule 500 mg twice daily orally (104562). A small clinical trial in patients with head and neck cancer and oral mucositis currently undergoing radiation therapy shows that applying a mucoadhesive film containing licorice to the upper lip mucosal surface four times daily for 4 weeks, in conjunction with standard oral care, improves pain scores, mucositis grading, and ulcer size when compared with placebo film (108572). The validity of this finding is limited due to the short duration of treatment and exclusion of patients with severe mucositis.
• Osteoarthritis. Although there has been interest in using oral licorice for osteoarthritis, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Osteoporosis. Although there has been interest in using oral licorice for osteoporosis, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Parkinson disease. It is unclear if oral licorice is beneficial for improving Parkinson disease symptoms. Details: A small clinical study in patients with Parkinson disease shows that taking licorice extract 136 mg (containing glycyrrhizin 12.14 mg, polyphenols 136 mcg, and flavonoids 2.6 mcg) in a 5 mL syrup twice daily for 6 months improves Parkinson symptoms, tremor, and overall daily activities when compared with placebo (102961).
• Peptic ulcers. Evidence for the use of oral licorice for peptic ulcers is mixed. Details: There is some evidence that taking 6-12 tablets each containing deglycyrrhizinated licorice 380 mg, bismuth subnitrate 100 mg, aluminum hydroxide gel 100 mg, magnesium carbonate 200 mg, sodium bicarbonate 100 mg, and powdered alder buckthorn bark 30 mg (Caved-S, Cedona) in up to three divided doses daily for 4-16 weeks might accelerate the healing of peptic ulcers (11312,11313). Some clinical research also shows that this product is as effective as carbenoxolone sodium (Biogastrone) when taken at doses of two tablets three times daily after meals for 4 weeks (59871). In contrast, taking deglycyrrhizinated licorice (Ulcedal, Cedona, and others) 450-1000 mg three to five times daily for 4-8 weeks or glycyrrhizinic acid-reduced licorice 760 mg three times daily for 6 weeks does not seem to reduce the need for medication, pain, burning, or other discomfort in patients with peptic ulcers when compared with placebo (59864,59865,59873,59874).
• Physical performance. It is unclear if oral licorice is beneficial for improving physical performance in older females. Details: A small clinical trial in healthy females 59 years and older shows that taking licorice flavonoid oil 300 mg orally daily for 16 weeks in addition to strength training does not improve walking speed or other measures of functional mobility when compared with strength training alone (102960).
• Polycystic ovary syndrome (PCOS). Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking licorice root extract 2250 mg daily along with Ceylon cinnamon, levant berry, St. John's Wort, peony, and tribulus for 3 months with lifestyle modification improves symptoms of PCOS, including a reduction in oligomenorrhea/amenorrhea by 33% and the number of days between menstrual cycles by 43 days when compared with lifestyle modification alone. Although conception rate increased 4-fold in the intervention group, live birth rate was similar between groups (97216). The effect of licorice alone for the treatment of PCOS is unknown.
• Prostate cancer. Although there has been interest in using oral licorice for prostate cancer, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Psoriasis. It is unclear if topical licorice is beneficial for improving psoriasis symptoms. Details: Preliminary clinical research shows that using a topical cream containing licorice extract and milk proteins twice daily for 4 weeks does not reduce the duration of corticosteroid cream therapy in patients with palmar and/or plantar psoriasis, but may improve skin peeling, the area of skin affected, and some subjective symptoms, when compared with corticosteroid cream alone (59823).
• Systemic lupus erythematosus (SLE). Although there has been interest in using oral licorice for SLE, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Tuberculosis. Although there has been interest in using oral licorice for tuberculosis, there is insufficient reliable information about the clinical effects of licorice for this condition.
• Urticaria. Oral licorice has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of clinical research in adults with chronic urticaria shows that taking compound glycyrrhizin, containing glycyrrhizin, N-acetyl cysteine, and glycine, as 50-75 mg three times daily along with desloratadine 5-8.8 mg daily for 4 weeks improves response rate, cure rate, and recurrence rate when compared with desloratadine alone (108571). However, most studies included in the meta-analysis were low quality, and all studies were conducted in China. Higher quality studies in other geographic locations are needed to confirm these findings.
• Vitiligo. It is unclear if the licorice constituent compound glycyrrhizin is beneficial for vitiligo. Details: A meta-analysis of 14 clinical studies in patients aged 3-68 years old with vitiligo shows that taking licorice constituent compound glycyrrhizin 25-75 mg 3 times daily for 2-6 months with standard treatment improves effectiveness, cure rate, and immune-mediated inflammatory markers when compared with standard treatment alone (112232). More evidence is needed to rate licorice for these uses.

(Read more about LICORICE)

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.
• 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).
• 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. Although there has been interest in using inhaled peppermint oil for menopausal symptoms, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Migraine headache. It is unclear if intranasal 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.
• 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.
• 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)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atopic dermatitis (eczema). A specific combination product (Zemaphyte, Phytopharm Plc) containing schizonepeta has been evaluated for atopic dermatitis. Although some preliminary clinical research shows that taking this combination product for 8 weeks to 12 months reduces skin lesions when compared to baseline (12627,12628,103902,103903), higher quality clinical research has not supported this finding (12630). In one high-quality, randomized, crossover study in Chinese patients aged 8-52 years, taking this combination product daily for 4 weeks, then twice weekly for 4 weeks, did not improve clinical symptoms when compared with placebo (12630). The combination product evaluated in these studies (Zemaphyte, Phytopharm Plc) contains undisclosed quantities of schizonepeta, Ledeboureilla seseloides, Potentilla chinensis, Aebia clematidis, rehmannia, peony, Lophatherum gracile, Dictamnus dasycarpus, tribulus, and licorice.br> More evidence is needed to rate schizonepeta for this use.

(Read more about SCHIZONEPETA)

POSSIBLY SAFE ...when asarabacca root extract verified to be aristolochic acid-free is used orally and appropriately short-term. Asarabacca root extract has been used with apparent safety in doses up to 30 mg daily (12,18).

POSSIBLY UNSAFE ...when asarabacca root extract verified to be aristolochic acid-free is used orally in large amounts or long-term (12). Large doses have been associated with significant side effects, including burning tongue, gastroenteritis, diarrhea, skin rashes, and partial paralysis (18). ...when the essential oil is taken orally. The essential oil contains a potential hepatocarcinogenic constituent, beta-asarone (12).

UNSAFE ...when aristolochic acid-contaminated asarabacca root extract is used orally. Asarabacca is commonly contaminated with aristolochic acid, which is nephrotoxic and carcinogenic. The US Food and Drug Administration (FDA) considers all products containing aristolochic acid to be unsafe and adulterated. Only products analytically verified to be aristolochic acid-free should be used (6118).

PREGNANCY: LIKELY UNSAFE
when used orally. Asarabacca might act as a menstrual or uterine stimulant (12); contraindicated.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about ASARABACCA)

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

POSSIBLY SAFE ...when licorice products that do not contain glycyrrhizin (deglycyrrhizinated licorice) are used orally and appropriately for medicinal purposes. Licorice flavonoid oil 300 mg daily for 16 weeks, and deglycyrrhizinated licorice products in doses of up to 4.5 grams daily for up to 16 weeks, have been used with apparent safety (6196,11312,11313,17727,100984,102960). ...when licorice products containing glycyrrhizin are used orally in low doses, short-term. Licorice extract 272 mg, containing glycyrrhizin 24.3 mg, has been used daily with apparent safety for 6 months (102961). A licorice extract 1000 mg, containing monoammonium glycyrrhizinate 240 mg, has been used daily with apparent safety for 12 weeks (110320). In addition, a syrup providing licorice extract 750 mg has been used twice daily with apparent safety for 5 days (104558). ...when applied topically. A gel containing 2% licorice root extract has been applied to the skin with apparent safety for up to 2 weeks. (59732). A mouth rinse containing 5% licorice extract has been used with apparent safety four times daily for up to one week (104564).

POSSIBLY UNSAFE ...when licorice products containing glycyrrhizin are used orally in large amounts for several weeks, or in smaller amounts for longer periods of time. The European Scientific Committee on Food recommends that a safe average daily intake of glycyrrhizin should not exceed 10 mg (108577). In otherwise healthy people, consuming glycyrrhizin daily for several weeks or longer can cause severe adverse effects including pseudohyperaldosteronism, hypertensive crisis, hypokalemia, cardiac arrhythmias, and cardiac arrest. Doses of 20 grams or more of licorice products, containing at least 400 mg glycyrrhizin, are more likely to cause these effects; however, smaller amounts have also caused hypokalemia and associated symptoms when taken for months to years (781,3252,15590,15592,15594,15596,15597,15599,15600,16058)(59731,59740,59752,59785,59786,59787,59792,59795,59805,59811)(59816,59818,59820,59822,59826,59828,59849,59850,59851,59867)(59882,59885,59888,59889,59895,59900,59906,97213,110305). In patients with hypertension, cardiovascular or kidney conditions, or a high salt intake, as little as 5 grams of licorice product or 100 mg glycyrrhizin daily can cause severe adverse effects (15589,15593,15598,15600,59726).

PREGNANCY: UNSAFE
when used orally. Licorice has abortifacient, estrogenic, and steroid effects. It can also cause uterine stimulation. Heavy consumption of licorice, equivalent to 500 mg of glycyrrhizin per week (about 250 grams of licorice per week), during pregnancy seems to increase the risk of delivery before gestational age of 38 weeks (7619,10618). Furthermore, high intake of glycyrrhizin, at least 500 mg per week, during pregnancy is associated with increased salivary cortisol levels in the child by the age of 8 years. This suggests that high intake of licorice during pregnancy may increase hypothalamic-pituitary-adrenocortical axis activity in the child (26434); avoid using.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about LICORICE)

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)

POSSIBLY UNSAFE ...when used orally in excessive amounts. Schizonepeta contains pulegone, a known hepatotoxin (12620,12626).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about SCHIZONEPETA)

(Read more about ASARABACCA)

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, licorice might reduce the effects of antihypertensive drugs.  Details In human research, licorice increases blood pressure in a dose-dependent manner (1372,7620,59877).

CISPLATIN (Platinol-AQ) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might reduce the effects of cisplatin.  Details In animal research, licorice diminished the therapeutic efficacy of cisplatin (59763).

CORTICOSTEROIDS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of licorice and corticosteroids might increase the side effects of corticosteroids.  Details Case reports suggest that concomitant use of licorice and oral corticosteroids, such as hydrocortisone, can potentiate the duration of activity and increase blood levels of corticosteroids (3252,12672,20040,20042,48429,59756). Additionally, in one case report, a patient with neurogenic orthostatic hypertension stabilized on fludrocortisone 0.1 mg twice daily developed pseudohyperaldosteronism after recent consumption of large amounts of black licorice (108568).

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might increase levels of drugs metabolized by CYP2B6.  Details In vitro research shows that licorice extract and glabridin, a licorice constituent, inhibit CYP2B6 isoenzymes (10300,94822). Licorice extract from the species G. uralensis seems to inhibit CYP2B6 isoenzymes to a greater degree than G. glabra extract in vitro (94822). Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2B6; however, these interactions have not yet been reported in humans.

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might increase levels of drugs metabolized by CYP2C19.  Details In vitro, licorice extracts from the species G. glabra and G. uralensis inhibit CYP2C19 isoenzymes in vitro (94822). Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2C19; however, this interaction has not yet been reported in humans.

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might increase levels of drugs metabolized by CYP2C8.  Details In vitro, licorice extract from the species G. glabra and G. uralensis inhibits CYP2C8 isoenzymes (94822). Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2C8; however, this interaction has not yet 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, licorice might increase or decrease levels of drugs metabolized by CYP2C9.  Details There is conflicting evidence about the effect of licorice on CYP2C9 enzyme activity. In vitro research shows that extracts from the licorice species G. glabra and G. uralensis moderately inhibit CYP2C9 isoenzymes (10300,94822). However, evidence from an animal model shows that licorice extract from the species G. uralensis can induce hepatic CYP2C9 activity (14441). Until more is known, licorice should be used cautiously in people taking CYP2C9 substrates.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP3A4.  Details Pharmacokinetic research shows that the licorice constituent glycyrrhizin, taken in a dosage of 150 mg orally twice daily for 14 days, modestly decreases the area under the concentration-time curve of midazolam by about 20%. Midazolam is a substrate of CYP3A4, suggesting that glycyrrhizin modestly induces CYP3A4 activity (59808). Animal research also shows that licorice extract from the species G. uralensis induces CYP3A4 activity (14441). However, licorice extract from G. glabra species appear to inhibit CYP3A4-induced metabolism of testosterone in vitro. It is thought that the G. glabra inhibits CYP3A4 due to its constituent glabridin, which is a moderate CYP3A4 inhibitor in vitro and not present in other licorice species (10300,94822). Until more is known, licorice should be used cautiously in people taking CYP3A4 substrates.

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of licorice with digoxin might increase the risk of cardiac toxicity.  Details Overuse or misuse of licorice with cardiac glycoside therapy might increase the risk of cardiac toxicity due to potassium loss (10393).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of licorice with diuretic drugs might increase the risk of hypokalemia.  Details Overuse of licorice might compound diuretic-induced potassium loss (10393,20045,20046,59812). In one case report, a 72-year-old male with a past medical history of hypertension, type 2 diabetes, hyperlipidemia, arrhythmia, stroke, and hepatic dysfunction was hospitalized with severe hypokalemia and uncontrolled hypertension due to pseudohyperaldosteronism. This was thought to be provoked by concomitant daily consumption of a product containing 225 mg of glycyrrhizin, a constituent of licorice, and hydrochlorothiazide 12.5 mg for 1 month (108577).

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might increase or decrease the effects of estrogen therapy.  Details Theoretically, licorice might interfere with estrogen therapy due to estrogenic and anti-estrogenic effects (7860,16058).

LOOP DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, loop diuretics might increase the mineralocorticoid effects of licorice.  Details Theoretically, loop diuretics might enhance the mineralocorticoid effects of licorice by inhibiting the enzyme that converts cortisol to cortisone; however, bumetanide (Bumex) does not appear to have this effect (3255).

METHOTREXATE (Trexall, others) Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, licorice might increase levels of methotrexate.  Details Animal research suggests that intravenous administration of glycyrrhizin, a licorice constituent, and high-dose methotrexate may delay methotrexate excretion and increase systemic exposure, leading to transient elevations in liver enzymes and total bilirubin (108570). This interaction has not yet been reported in humans.

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, licorice might decrease levels of midazolam.  Details In humans, the licorice constituent glycyrrhizin appears to moderately induce the metabolism of midazolam (59808). This is likely due to induction of cytochrome P450 3A4 by licorice. Until more is known, licorice should be used cautiously in people taking midazolam.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might decrease the absorption of P-glycoprotein substrates.  Details In vitro research shows that licorice can increase P-glycoprotein activity (104561).

PACLITAXEL (Abraxane, Onxol) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might decrease plasma levels and clinical effects of paclitaxel.  Details Multiple doses of licorice taken concomitantly with paclitaxel might reduce the effectiveness of paclitaxel. Animal research shows that licorice 3 grams/kg given orally for 14 days before intravenous administration of paclitaxel decreases the exposure to paclitaxel and increases its clearance. Theoretically, this occurs because licorice induces cytochrome P450 3A4 enzymes, which metabolize paclitaxel. Notably, a single dose of licorice did not affect exposure or clearance of paclitaxel (102959).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, licorice might decrease plasma levels and clinical effects of warfarin.  Details Licorice seems to increase metabolism and decrease levels of warfarin in animal models. This is likely due to induction of cytochrome P450 2C9 (CYP2C9) metabolism by licorice (14441). Advise patients taking warfarin to avoid taking licorice.

(Read more about LICORICE)

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)

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Animal research suggests that schizonepetin, a monoterpene constituent of schizonepeta, inhibits cytochrome P450 (CYP) 1A2 (94787). Theoretically, schizonepeta might increase the effects and side effects of CYP1A2 substrates.  Details Some substrates of CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), and others.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Animal research suggests that schizonepetin, a monoterpene constituent of schizonepeta, inhibits cytochrome P450 (CYP) 2D6 (94787). Theoretically, schizonepeta might increase the effects and side effects of CYP2D6 substrates.  Details Some substrates of CYP2D6 include amitriptyline (Elavil), codeine, desipramine (Norpramin), flecainide (Tambocor), haloperidol (Haldol), imipramine (Tofranil), metoprolol (Lopressor, Toprol XL), ondansetron (Zofran), paroxetine (Paxil), risperidone (Risperdal), tramadol (Ultram), venlafaxine (Effexor), and others.

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Animal research suggests that schizonepetin, a monoterpene constituent of schizonepeta, inhibits cytochrome P450 (CYP) 2E1 (94787). Theoretically, schizonepeta might increase the effects and side effects of CYP2E1 substrates.  Details Some substrates of CYP2E1 include acetaminophen, chlorzoxazone (Parafon Forte), ethanol, theophylline, and anesthetics such as enflurane (Ethrane), halothane (Fluothane), isoflurane (Forane), and methoxyflurane (Penthrane).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Animal research suggests that schizonepetin, a monoterpene constituent of schizonepeta, induces cytochrome P450 (CYP) 3A4 (94787). Theoretically, schizonepeta might decrease the effects of CYP3A4 substrates.  Details Some substrates of CYP3A4 include lovastatin (Mevacor), ketoconazole (Nizoral), itraconazole (Sporanox), fexofenadine (Allegra), triazolam (Halcion), and numerous others.

(Read more about SCHIZONEPETA)

General ...Orally, asarabacca seems to be well tolerated when used appropriately (12). However, large doses may cause nausea and vomiting (12). Severe poisoning has also been reported (553). Symptoms of poisoning include burning of tongue, gastroenteritis, diarrhea, skin rashes, and partial paralysis (18). Also, asarabacca is commonly contaminated with aristolochic acid, which is nephrotoxic and carcinogenic (6118). The FDA considers all products containing aristolochic acid to be unsafe and adulterated (6118).

Dermatologic ...Orally, symptoms of asarabacca poisoning include skin rashes (18).

Gastrointestinal ...Orally, large doses of asarabacca may cause nausea and vomiting (12). Severe poisoning has also been reported (553). Symptoms of poisoning include burning of tongue, gastroenteritis, and diarrhea (18).

Neurologic/CNS ...Orally, symptoms of asarabacca poisoning include partial paralysis (18).

Oncologic ...Asarabacca is frequently contaminated with aristolochic acid, which is carcinogenic. The FDA considers all products containing aristolochic acid to be unsafe and adulterated (6118).

Renal ...Asarabacca is frequently contaminated with aristolochic acid, which is nephrotoxic (6118). The FDA considers all products containing aristolochic acid to be unsafe and adulterated (6118).

(Read more about ASARABACCA)

General ...Orally, licorice is generally well tolerated when used in amounts commonly found in foods. It seems to be well tolerated when licorice products that do not contain glycyrrhizin (deglycyrrhizinated licorice) are used orally and appropriately for medicinal purposes or when used topically, short-term.
Most Common Adverse Effects:
Orally: Headache, nausea, and vomiting.
Topically: Contact dermatitis.
Intravenously: Diarrhea, itching, nausea, and rash.
Serious Adverse Effects (Rare):
Orally: Case reports have raised concerns about acute renal failure, cardiac arrest, cardiac arrhythmias, hypertension, hypokalemia, muscle weakness, paralysis, pseudohyperaldosteronism, and seizure associated with long-term use or large amounts of licorice containing glycyrrhizin.

Cardiovascular ...Orally, excessive licorice ingestion can lead to pseudohyperaldosteronism, which can precipitate cardiovascular complications such as hypertension and hypertensive crisis, ventricular fibrillation or tachycardia, sinus pause, and cardiac arrest. These effects are due to the licorice constituent glycyrrhizin and usually occur when 20-30 grams or more of licorice product is consumed daily for several weeks (781,15590,15592,15594,15596,15597,15599,15600,16835,97213) (104563,108574,108576,110305,112234). In one case report, an 89-year-old female taking an herbal medicine containing licorice experienced a fatal arrhythmia secondary to licorice-induced hypokalemia. The patient presented to the hospital with recurrent syncope, weakness, and fatigue for 5 days after taking an herbal medicine containing licorice for 2 months. Upon admission to the hospital, the patient developed seizures, QT prolongation, and ventricular arrhythmia requiring multiple defibrillations. Laboratory tests confirmed hypokalemia and pseudohyperaldosteronism (112234).
However, people with cardiovascular or kidney conditions may be more sensitive, so these adverse events may occur with doses as low as 5 grams of licorice product or glycyrrhizin 100 mg daily (15589,15593,15598,15600,59726). A case report in a 54-year-old male suggests that malnutrition might increase the risk of severe adverse effects with excessive licorice consumption. This patient presented to the emergency room with cardiac arrest and ventricular fibrillation after excessive daily consumption of licorice for about 3 weeks. This caused pseudohyperaldosteronism and then hypokalemia, leading to cardiovascular manifestations. In spite of resuscitative treatment, the patient progressed to kidney failure, refused dialysis, and died shortly thereafter (103791).

Dermatologic ...There have been reports of contact allergy, resulting in an itchy reddish eruption, occurring in patients that applied cosmetic products containing oil-soluble licorice extracts (59912). There have also been at least 3 cases of allergic contact dermatitis reported with the topical application of glycyrrhizin-containing products to damaged skin. In one case report, a 31-year-old female with acne presented with a 2-year history of pruritic erythematous-scaly plaques located predominantly on the face and neck after the use of a cosmetic product containing licorice root extract 1%. The patient had a positive skin patch test to licorice root extract, leading the clinicians to hypothesize that the use of benzoyl peroxide, a strong irritant, might have sensitized the patient to licorice (108578). Burning sensation, itching, redness, and scaling were reported rarely in patients applying a combination of licorice, calendula, and snail secretion filtrate to the face. The specific role of licorice is unclear (110322).
In rare cases, the glycyrrhizin constituent of licorice has caused rash and itching when administered intravenously (59712).

Endocrine ...Orally, excessive licorice ingestion can cause a syndrome of apparent mineralocorticoid excess, or pseudohyperaldosteronism, with sodium and water retention, increased urinary potassium loss, hypokalemia, and metabolic alkalosis due to its glycyrrhizin content (781,10619,15591,15592,15593,15594,15595,15596,15597,15598)(15600,16057,16835,25659,25660,25673,25719,26439,59818,59822)(59832,59864,91722,104563,108568,108574,110305,112234). These metabolic abnormalities can lead to hypertension, edema, EKG changes, fatigue, syncope, arrhythmias, cardiac arrest, headache, lethargy, muscle weakness, dropped head syndrome (DHS), rhabdomyolysis, myoglobinuria, paralysis, encephalopathy, respiratory impairment, hyperparathyroidism, and acute kidney failure (10393,10619,15589,15590,15593,15594,15596,15597,15599)(15600,16057,16835,25660,25673,25719,26439,31562,59709,59716)(59720,59740,59787,59820,59826,59882,59889,59900,91722,97214,100522) (104563,108576,108577). These effects are most likely to occur when 20-30 grams of licorice products containing glycyrrhizin 400 mg or more is consumed daily for several weeks (781,15590,15592,15594,15596,15597,15599,15600,16835,108574). However, some people may be more sensitive, especially those with hypertension, diabetes, heart problems, or kidney problems (15589,15593,15598,15600,59726,108576,108577) and even low or moderate consumption of licorice may cause hypertensive crisis or hypertension in normotensive individuals (1372,97213). The use of certain medications with licorice may also increase the risk of these adverse effects (108568,108577). One case report determined that the use of large doses of licorice in an elderly female stabilized on fludrocortisone precipitated hypokalemia and hypertension, requiring inpatient treatment (108568). Another case report describes severe hypokalemia necessitating intensive care treatment due to co-ingestion of an oral glycyrrhizin-specific product and hydrochlorothiazide for 1 month (108577). Glycyrrhetinic acid has a long half-life, a large volume of distribution, and extensive enterohepatic recirculation. Therefore, it may take 1-2 weeks before hypokalemia resolves (781,15595,15596,15597,15600). Normalization of the renin-aldosterone axis and blood pressure can take up to several months (781,15595,108568). Treatment typically includes the discontinuation of licorice, oral and intravenous potassium supplementation, and short-term use of aldosterone antagonists, such as spironolactone (108574,108577).
Chewing tobacco flavored with licorice has also been associated with toxicity. Chewing licorice-flavored tobacco, drinking licorice tea, or ingesting large amounts of black licorice flavored jelly beans or lozenges has been associated with hypertension and suppressed renin and aldosterone levels (12671,12837,97214,97215,97217,108574). One case report suggests that taking a combination product containing about 100 mg of licorice and other ingredients (Jintan, Morishita Jintan Co.) for many decades may be associated with hypoaldosteronism, even up to 5 months after discontinuation of the product (100522). In another case report, licorice ingestion led to hyperprolactinemia in a female (59901). Licorice-associated hypercalcemia has also been noted in a case report (59766).

Gastrointestinal ...Nausea and vomiting have been reported rarely following oral use of deglycyrrhizinated licorice (25694,59871). Intravenously, the glycyrrhizin constituent of licorice has rarely caused gastric discomfort, diarrhea, or nausea (59712,59915).

Immunologic ...There have been reports of contact allergy, resulting in an itchy reddish eruption, occurring in patients that applied cosmetic products containing oil-soluble licorice extracts (59912). There have also been at least 3 cases of allergic contact dermatitis reported with the topical application of glycyrrhizin-containing products to damaged skin. In one case report, a 31-year-old female with acne presented with a 2-year history of pruritic erythematous-scaly plaques located predominantly on the face and neck after the use of a cosmetic product containing licorice root extract 1%. The patient had a positive skin patch test to licorice root extract, leading the clinicians to hypothesize that the use of benzoyl peroxide, a strong irritant, might have sensitized the patient to licorice (108578).

Musculoskeletal ...In a case report, excessive glycyrrhizin-containing licorice consumption led to water retention and was thought to trigger neuropathy and carpal tunnel syndrome (59791).

Neurologic/CNS ...Orally, licorice containing larger amounts of glycyrrhizin may cause headaches. A healthy woman taking glycyrrhizin 380 mg daily for 2 weeks experienced a headache (59892). Intravenously, the glycyrrhizin constituent of licorice has rarely caused headaches or fatigue (59721). In a case report, licorice candy ingestion was associated with posterior reversible encephalopathy syndrome accompanied by a tonic-clonic seizure (97218).

Ocular/Otic ...Orally, consuming glycyrrhizin-containing licorice 114-909 grams has been associated with transient visual loss (59714).

Pulmonary/Respiratory ...Orally, large amounts of licorice might lead to pulmonary edema. In one case report, a 64-year old male consumed 1020 grams of black licorice (Hershey Twizzlers) containing glycyrrhizin 3.6 grams over 3 days, which resulted in pulmonary edema secondary to pseudohyperaldosteronism (31561). Intravenously, the glycyrrhizin constituent of licorice has caused cold or flu-like symptoms, although these events are not common (59712,59721).

(Read more about LICORICE)

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)

General ...There is currently a limited amount of information available about the adverse effects of schizonepeta. Orally, a specific combination product (Zemaphyte, Phytopharm Plc) containing schizonepeta and numerous other ingredients has been reported to cause nausea, vomiting, colic, dyspepsia, dizziness, headache, and hair loss (12627,12630). However, it is unclear if these effects are due to schizonepeta or the other ingredients.
High doses of schizonepeta may be hepatotoxic due to its pulegone constituent (12620,12626).

Gastrointestinal ...Orally, a specific combination product (Zemaphyte, Phytopharm Plc) containing schizonepeta and numerous other ingredients has been reported to cause nausea, vomiting, colic, and dyspepsia (12627,12630). However, it is unclear if these effects are due to schizonepeta or the other ingredients.

Hepatic ...Schizonepeta contains pulegone, a hepatotoxin. When taken orally in high doses, schizonepeta may be hepatotoxic due to this constituent (12620,12626).

Neurologic/CNS ...Orally, a specific combination product (Zemaphyte, Phytopharm Plc) containing schizonepeta and numerous other ingredients has been reported to cause dizziness and headache (12627,12630). However, it is unclear if these effects are due to schizonepeta or the other ingredients.

(Read more about SCHIZONEPETA)