Star Anise • Bitter Orange • Carqueja • Peppermint • Boldo .
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Below is general information about the effectiveness of the known ingredients contained in the product Digestazon. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
There is insufficient reliable information available about the effectiveness of carqueja.
INSUFFICIENT RELIABLE EVIDENCE to RATE
There is insufficient reliable information available about the effectiveness of star anise.
Below is general information about the safety of the known ingredients contained in the product Digestazon. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Bitter orange has Generally Recognized as Safe (GRAS) status in the US (4912,35751).
POSSIBLY SAFE ...when bitter orange essential oil is used topically or by inhalation as aromatherapy (6972,7107,98331,104186,104187,108642).
POSSIBLY UNSAFE ...when used orally for medicinal purposes. Although single doses of synephrine, or low daily doses used short-term, may be safe in healthy adults (2040,11269,15381,35757,35759,91681,97256,98332), laboratory analyses raise concerns that many marketed bitter orange products contain higher amounts of synephrine and other natural and synthetic amines than on the label, increasing the risk for serious stimulant-related adverse effects (104185). Additionally, there is a lack of agreement regarding a safe daily dose of synephrine. Health Canada has approved 50 mg of p-synephrine daily when used alone, or 40 mg of p-synephrine in combination with up to 320 mg of caffeine daily in healthy adults (91684). The Federal Institute for Risk Assessment in Germany recommends that supplements should provide no more than 6.7 mg of synephrine daily. This recommendation is meant to ensure that patients who frequently consume synephrine in conventional foods will receive no more than 25.7 mg daily (91290). These limits are intended to reduce the risk for serious adverse effects. There have been several case reports of ischemic stroke and cardiotoxicity including tachyarrhythmia, cardiac arrest, syncope, angina, myocardial infarction, ventricular arrhythmia, and death in otherwise healthy patients who have taken bitter orange extract alone or in combination with other stimulants such as caffeine (2040,6979,12030,13039,13067,14326,14342,91680).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in the amounts found in foods.
Bitter orange has Generally Recognized as Safe (GRAS) status in the US (4912).
PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally for medicinal purposes.
There are case reports of cardiotoxicity including tachyarrhythmia, syncope, and myocardial infarction in otherwise healthy adults who have taken bitter orange extract alone or in combination with other stimulants such as caffeine (2040,6979,12030,13039,13067,14326,14342,91680). The effects of bitter orange during lactation are unknown; avoid use.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Boldo has Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).
POSSIBLY UNSAFE ...when used orally in medicinal amounts. The volatile oil (2.5% in the leaf) contains the liver toxin ascaridole (4). Boldo has also been linked to a documented case of liver damage (13178). If boldo preparations are taken for medicinal purposes, only ascaridole-free preparations should be used. There is insufficient reliable information available about the safety of boldo when used topically.
PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in medicinal amounts.
In animals, boldo and the constituent boldine have abortive and teratogenic effects (100302). Also, the ascaridole constituent of boldo is a liver toxin (4).
There is insufficient reliable information available about the safety of carqueja.
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
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.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Star anise has Generally Recognized as Safe (GRAS) status in the US (4912).
POSSIBLY UNSAFE ...when star anise is used orally as a tea. In 2003, the US Food and Drug Administration (FDA) issued an advisory to the public not to consume teas brewed from star anise. They have been associated with adverse neurological and gastrointestinal effects, including jitteriness, irritability, tachycardia, nystagmus, vomiting, diarrhea, and seizures. Star anise products associated with these symptoms are often found to be contaminated with Japanese star anise (Illicium anisatum), which has known toxicity (11384,13058,76290,76293,100159,108932). However, large doses of star anise can also cause neurotoxicity (108932).
CHILDREN: POSSIBLY UNSAFE
when used orally.
Star anise tea is a traditional remedy for infant colic, but has been associated with adverse neurological and gastrointestinal effects, including jitteriness, irritability, tachycardia, nystagmus, vomiting, diarrhea, and seizures. Star anise products associated with these symptoms are often found to be contaminated with Japanese star anise (Illicium anisatum), which has known toxicity (11384,13058,76290,76293,100159,108932). However, large doses of star anise can also cause neurotoxicity (108932).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (4912).
PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when star anise is used orally as a tea.
In 2003, the US Food and Drug Administration (FDA) issued an advisory to the public not to consume teas brewed from star anise, as they have been associated with adverse neurological and gastrointestinal effects (11384,13058,76290,76293,100159,108932).
Below is general information about the interactions of the known ingredients contained in the product Digestazon. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, bitter orange might increase the risk of hypoglycemia when taken with antidiabetes drugs.
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Some clinical research shows that drinking a tea containing bitter orange and Indian snakeroot reduces fasting and postprandial glucose levels in patients with type 2 diabetes who are using antidiabetes drugs (35751). However, it is unclear if these effects are due to bitter orange, Indian snakeroot, or the combination. An animal study also shows that p-synephrine in combination with gliclazide , a sulfonylurea, causes an additional 20% to 44% decrease in glucose levels when compared with gliclazide alone (95658).
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Bitter orange might increase blood pressure and heart rate when taken with caffeine.
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Bitter orange might affect colchicine levels.
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Colchicine is a substrate of P-glycoprotein and cytochrome P450 3A4 (CYP3A4). Bitter orange has been reported to inhibit CYP3A4 and increase levels of CYP3A4 substrates (7029,11362,93470). However, one small clinical study in healthy adults shows that drinking bitter orange juice 240 mL twice daily for 4 days and taking a single dose of colchicine 0.6 mg on the 4th day decreases colchicine peak serum levels by 24%, time to peak serum level by 1 hour, and overall exposure to colchicine by 20% (35762). The clinical significance of this finding is unclear.
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Theoretically, bitter orange might increase levels of drug metabolized by CYP2D6.
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In vitro research shows that octopamine, a constituent of bitter orange, weakly inhibits CYP2D6 enzymes (91878). This effect has not been reported in humans.
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Bitter orange might increase levels of drugs metabolized by CYP3A4.
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Small clinical studies suggest that single or multiple doses of freshly squeezed bitter orange juice 200-240 mL can inhibit CYP3A4 metabolism of drugs (7029,11362,93470), causing increased drug levels and potentially increasing the risk of adverse effects. However, the extent of the effect of bitter orange on CYP3A4-mediated drug interactions is unknown. Some evidence suggests that bitter orange selectively inhibits intestinal CYP3A4, but not hepatic CYP3A4. Its effect on P-glycoprotein, which strongly overlaps with CYP3A4 interactions, is unclear (7029,11269,11270,11362). One small clinical study shows that drinking 8 ounces of freshly squeezed bitter orange juice has no effect on cyclosporine, which seems to be more dependent on hepatic CYP3A4 and P-glycoprotein than intestinal CYP3A4 (11270).
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Bitter orange might increase blood levels of dextromethorphan.
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One small clinical study shows that bitter orange juice increases dextromethorphan levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition (11362). Theoretically, bitter orange might increase the risk for dextromethorphan-related adverse effects.
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Bitter orange might increase blood levels of felodipine.
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One small clinical study shows that bitter orange juice increases felodipine levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition (7029). Theoretically, bitter orange might increase the risk for felodipine-related adverse effects.
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Bitter orange might increase blood levels of indinavir.
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One small clinical study shows that bitter orange juice slightly increases indinavir levels, but this effect is likely to be clinically insignificant. Bitter orange selectively inhibits intestinal cytochrome P450 3A4 (CYP3A4); however, the metabolism of indinavir seems to be more dependent on hepatic CYP3A4 (11269). The effect of bitter orange on other protease inhibitors has not been studied.
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Bitter orange might increase blood levels of midazolam.
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One small clinical study shows that bitter orange juice can increase midazolam levels, likely through inhibition of cytochrome P450 3A4 (CYP3A4) (7029). Theoretically, bitter orange might increase the risk of midazolam-related adverse effects.
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Theoretically, taking MAOIs with synephrine-containing bitter orange preparations might increase the hypertensive effects of synephrine, potentially leading to hypertensive crisis.
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Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.
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One case report suggests that taking bitter orange in combination with other stimulants such as caffeine might prolong the QT interval in some patients (13039).
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Bitter orange juice might increase blood levels of sildenafil.
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A small clinical study in healthy adult males shows that drinking freshly squeezed bitter orange juice 250 mL daily for 3 days and taking a single dose of sildenafil 50 mg on the 3rd day increases the peak plasma concentration of sildenafil by 18% and the overall exposure to sildenafil by 44%. Theoretically, this may be due to inhibition of cytochrome P450 3A4 by bitter orange (93470).
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Theoretically, bitter orange might increase the risk of hypertension and adverse cardiovascular effects when taken with stimulant drugs.
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Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.
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Animal and in vitro research shows that boldine, a constituent of boldo, has antiplatelet activity (5191,36789). In one case report, an adult taking a combination of boldo and fenugreek with warfarin experienced an increase in international normalized ratio (INR); however, it is unclear if this effect was due to boldo, fenugreek, the combination, or another factor (5191).
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Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.
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Theoretically, taking boldo with lithium might increase the levels and clinical effects of lithium.
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Boldo is believed to have diuretic effects (4). Theoretically, these diuretic effects might reduce the excretion of lithium. The dose of lithium might need to be decreased.
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Taking boldo with tacrolimus may decrease the levels and clinical effects of tacrolimus, potentially increasing the risk of transplant rejection.
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In one case report, a patient with a long-term history of stable tacrolimus levels developed subtherapeutic levels after taking boldo 300 mg twice daily orally for several weeks. Tacrolimus levels returned to normal after discontinuing boldo. However, the mechanism of this interaction is unclear (92601).
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Theoretically, carqueja might lower blood glucose levels (13585,13588) and might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels closely. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.
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Theoretically, peppermint oil might increase the levels and adverse effects of cyclosporine.
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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.
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Theoretically, peppermint might increase the levels of CYP1A2 substrates.
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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).
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Theoretically, peppermint might increase the levels of CYP2C19 substrates.
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In vitro research shows that peppermint oil inhibits CYP2C19 (12479). So far, this interaction has not been reported in humans.
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Theoretically, peppermint might increase the levels of CYP2C9 substrates.
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In vitro research shows that peppermint oil inhibits CYP2C9 (12479). So far, this interaction has not been reported in humans.
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Theoretically, peppermint might increase the levels of CYP3A4 substrates.
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Below is general information about the adverse effects of the known ingredients contained in the product Digestazon. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally, bitter orange might be unsafe when used in medicinal amounts.
Topically and when inhaled as aromatherapy, bitter orange seems to be well tolerated.
Most Common Adverse Effects:
Orally: Hypertension and tachycardia, particularly when used in combination with caffeine and/or other stimulant ingredients.
Topically: Skin irritation.
Serious Adverse Effects (Rare):
Orally: Myocardial infarction, QT prolongation, seizures, stroke, syncope, tachyarrhythmia, and ventricular fibrillation have been reported in patients taking bitter orange in combination with other ingredients. It is unclear if these effects are due to bitter orange, other ingredients, or the combination.
Cardiovascular
...Bitter orange, which contains adrenergic agonists synephrine and octopamine, may cause hypertension and cardiovascular toxicity when taken orally (2040,6969,6979).
Studies evaluating the effect of bitter orange on cardiovascular parameters have been mixed. Several studies show that taking bitter orange alone or in combination with caffeine increases blood pressure and heart rate. In one clinical study, bitter orange in combination with caffeine increased systolic and diastolic blood pressure and heart rate in otherwise healthy normotensive adults (13657). In another study, a single dose of bitter orange 900 mg, standardized to 6% synephrine (54 mg), also increased systolic and diastolic blood pressure and heart rate for up to 5 hours in young, healthy adults (13774). Using half that dose of bitter orange and providing half as much synephrine, did not seem to significantly increase blood pressure or QT interval in healthy adults (14311). Increased diastolic, but not systolic, blood pressure or heart rate also occurred in a clinical trial involving a specific supplement containing synephrine 21 mg and caffeine 304 mg (Ripped Fuel Extreme Cut, Twinlab) (35743). Synephrine given intravenously to males increased systolic blood pressure, but lacked an effect on diastolic blood pressure or heart rate (12193).
In clinical research and case reports, tachycardia, tachyarrhythmia, QT prolongation, ischemic stroke, variant angina, and myocardial infarction have occurred with use of bitter orange or synephrine-containing multi-ingredient products (12030,13039,13067,13091,13657,14326,35749,91680). In one case report, a combination product containing bitter orange may have masked bradycardia and hypotension while exacerbating weight loss in a 16 year-old female with an eating disorder taking the product for weight loss (35740). From 1998 to 2004, Health Canada received 16 reports of serious adverse cardiovascular reactions such as tachycardia, cardiac arrest, ventricular fibrillation, blackout, and collapse. In two of these cases, the patient died. In almost all of these cases, bitter orange was combined with another stimulant such as caffeine, ephedrine, or both (14342).
Other research has found no significant effect of bitter orange on blood pressure or heart rate. Several clinical studies have reported that, when taken as a single dose or in divided doses ranging from 20-100 mg for one day, p-synephrine had no significant effect on blood pressure, heart rate, electrocardiogram results or adverse cardiovascular events in healthy adults (35772,91681,91681,95659,101708) Similarly, no difference in blood pressure, heart rate or electrocardiogram results were reported when p-synephrine from bitter orange (Advantra Z/Kinetic; Nutratech/Novel Ingredients Inc.) was taken for 6 weeks in healthy patients (11268). Another clinical study showed no significant effect of bitter orange (Nutratech Inc.), standardized to synephrine 20 mg, on blood pressure or heart rate when taken daily for 8 weeks in healthy males (95656). In other research, changes in blood pressure, heart rate, or QTc interval were lacking when bitter orange was given alone or in combination with caffeine and green tea (14311,35753,35755,35764,35769,35770). In one study of healthy adults, taking a single dose of p-synephrine 103 mg actually reduced mean diastolic blood pressure by 0.4-4 mmHg at 1 and 2 hours after administration when compared with placebo (95659).
A meta-analysis of clinical trials in adults with or without obesity suggests that taking p-synephrine 6-214 mg orally daily does not affect blood pressure or heart rate when used short-term, but modestly increases blood pressure and heart rate when taken for 56-60 days (109950).
The effect of bitter orange on blood pressure, heart rate, and electrocardiogram results in patients with underlying conditions, particularly cardiovascular disease, is unknown and requires further study.
Dermatologic ...Photosensitivity may occur, particularly in fair-skinned people (11909). In a clinical trial, topical application with bitter orange essential oil resulted in irritation (6972).
Endocrine ...Some clinical research shows that taking a specific supplement containing 21 mg of synephrine and 304 mg of caffeine (Ripped Fuel Extreme Cut, Twinlab) increases levels of postprandial glucose (35743). Other preliminary clinical research shows that taking a specific pre-workout supplement (Cellucor C4 Pre-Workout, Nutrabolt) along with a bitter orange extract standardized for synephrine 20 mg (Nutratech Inc.) 30 minutes once before exercise causes a significant 12% increase in glucose (95657); however, there is no difference in blood glucose when compared with placebo when this combination is taken daily for 8 weeks (95656). The effect of bitter orange itself is unclear.
Gastrointestinal ...Bitter orange has been linked to a report of ischemic colitis. In one case, a 52-year-old female developed ischemic colitis after taking a bitter orange-containing supplement (NaturalMax Skinny Fast, Nutraceutical Corporation) for a week. Symptoms resolved within 48 hours after discontinuing the supplement (15186). As this product contains various ingredients, the effect of bitter orange itself is unclear.
Musculoskeletal ...Unsteady gait has been noted in one case report of a patient taking bitter orange (13091). In another case, an otherwise healthy, Black male with sickle cell trait, developed severe rhabdomyolysis following ingestion of a specific weight loss product (Lipo 6, Nutrex Research Inc.), which contained synephrine and caffeine (16054). However, other preliminary clinical research shows that taking a specific pre-workout supplement (Cellucor C4 Pre-Workout, Nutrabolt) along with a bitter orange extract standardized for synephrine 20 mg (Nutratech Inc.), taken 30 minutes once before exercise (95657) or daily for 8 weeks, does not affect creatine kinase or serum creatinine levels when compared with placebo (95656). As these products contain various ingredients, the effect of bitter orange itself is unclear.
Neurologic/CNS ...Dizziness, difficulty in concentrating, memory loss, syncope, seizure, and stroke have been noted in case reports following bitter orange administration (13091,13039). Theoretically, bitter orange may trigger a migraine or cluster headache due to its synephrine and octopamine content (35768). When used as aromatherapy, bitter orange essential oil has also been reported to cause headache in some patients (104187). Sprint athletes taking the bitter orange constituent p-synephrine 3 mg/kg (Synephrine HCL 99%, Nutrition Power) 60 minutes before exercises and sprinting reported more nervousness (mean difference 0.9) when compared with placebo on a Likert scale. Although statistically significant, this difference is not considered clinically significant (95655).
General
...Orally, boldo is generally well tolerated when used in amounts commonly found in foods.
However, when used in medicinal amounts, boldo can cause significant adverse effects such as hepatotoxicity. There is currently a limited amount of information on the adverse effects of topical boldo; however, a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Orally: Abdominal pain, nausea, vomiting.
Topically: Dermatitis.
Severe Adverse Effects (Rare):
Orally: Hepatotoxicity, jaundice.
Cardiovascular ...In one report, a 39-year-old obese female developed palpitations and syncope after taking a weight loss supplement containing a combination of boldo, dandelion, and bladderwrack for 3 weeks. The patient was found to have prolonged QT-interval on ECG and frequent episodes of sustained polymorphic ventricular tachycardia (14321). It is not clear whether boldo, another ingredient, or the combination of ingredients is responsible for this adverse effect. The product was not analyzed to determine the presence of any potential toxic contaminants.
Dermatologic ...Topically, boldo can be irritating when applied to the skin (4). In one case report, a healthy 64-year-old patient experienced allergic contact dermatitis in an airborne pattern on the face, arms, and dorsum of both hands following airborne exposure to boldo. After exposure to boldo was avoided, the dermatitis resolved (106433).
Gastrointestinal ...In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male developed abdominal discomfort with gastrointestinal upset including heartburn (13178). In another case, a 72-year-old female reported nausea, vomiting, and anorexia, which were thought to be associated with hepatotoxic effects of a boldo infusion (100304).
Hepatic ...Orally, boldo is thought to potentially cause hepatotoxicity. The volatile oil from the boldo leaf contains the liver toxin, ascaridole. In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male with mild hepatic steatosis and very small gallbladder stones developed elevated liver transaminase levels. Levels normalized following discontinuation of the herbal product (13178). Several other cases of hepatotoxicity have been reported in elderly patients who received infusions of boldo leaves. These patients presented with elevated liver transaminase and bilirubin levels, sometimes up to 200 times the upper limit of normal, as well as nausea, vomiting, anorexia, asthenia, and jaundice. Lab tests and symptoms normalized a few days after stopping boldo (100304,106431).
Immunologic ...Boldo intake has been linked to one case of IgE-mediated anaphylactic allergic reaction (13185).
General ...No adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.
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).
General
...Orally, star anise is generally well tolerated when consumed in the amounts commonly found in food.
However, star anise tea is associated with serious neurological adverse effects which may or may not be related to contamination with Japanese star anise (Illicium apisatum).
Serious Adverse Effects (Rare):
Orally: Tea made from star anise has been associated with increased deep tendon reflexes, irritability, jitteriness, rapid eye movements, seizures, and vomiting. However, it is unclear if these effects are due to star anise or contamination with Japanese star anise (Illicium apisatum), which is known to be toxic due to its anisatin constituents.
Dermatologic ...Topically, the anethole constituent of star anise can cause dermatitis, including erythema, scaling, and vesiculation (13668,13669).
Gastrointestinal ...Orally, star anise tea has been reported to cause vomiting, diarrhea, and abdominal distension. The teas consumed in these reports may or may not have been contaminated with Japanese star anise (Illicum apisatum) (10407,13058,100159,108932).
Immunologic ...Topically, star anise and the constituents anethole, alpha-pinene, limonene, and safrole can cause allergic reactions in sensitive individuals (13669,76299).
Neurologic/CNS ...Orally, star anise tea has been reported to cause acute onset of irritability, jitteriness, hyperexcitability, clonus or myoclonus, increased deep tendon reflexes, rapid eye movements, nystagmus, and seizures. The teas consumed in these reports may or may not have been contaminated with Japanese star anise (Illicum apisatum) (10407,11384,13058,100159,108932).