Below is general information about the effectiveness of the known ingredients contained in the product Licorice + Garlic. 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
Below is general information about the safety of the known ingredients contained in the product Licorice + Garlic. 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 and appropriately. Garlic has been used safely in clinical studies lasting up to 7 years without reports of significant toxicity (1873,4782,4783,4784,4785,4786,4787,4789,4790,4797)(4798,6457,6897,14447,96008,96009,96014,102016,102670,103479)(107238,107239,107352,108607,110722,111763).
POSSIBLY SAFE ...when used topically. Garlic-containing gels, lipid-soluble garlic extracts, garlic pastes, and garlic mouthwashes have been safely used in clinical research for up to 3 months (4766,4767,8019,15030,51330,51386). ...when used intravaginally. A vaginal cream containing garlic and thyme has been safely used nightly for 7 nights (88387).
POSSIBLY UNSAFE ...when raw garlic is used topically (585). Raw garlic might cause severe skin irritation when applied topically.
PREGNANCY: LIKELY SAFE
when used orally in amounts commonly found in foods (3319).
PREGNANCY: POSSIBLY UNSAFE
when used orally in medicinal amounts.
Garlic is reported to have abortifacient activity (11020). One study also suggests that garlic constituents are distributed to the amniotic fluid after a single dose of garlic (4828). However, there are no published reports of garlic adversely affecting pregnancy. In clinical research, garlic 800 mg daily was used during the third trimester of pregnancy with no reported adverse outcomes (9201,51626). There is insufficient reliable information available about the safety of topical garlic during pregnancy.
LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (3319).
LACTATION: POSSIBLY UNSAFE
when used orally in amounts greater than those found in foods.
Several small studies suggest that garlic constituents are secreted in breast milk, and that nursing infants of mothers consuming garlic are prone to extended nursing (3319,4829,4830). There is insufficient reliable information available about the safety of topical garlic during lactation.
CHILDREN: POSSIBLY SAFE
when used orally and appropriately for up to 8 weeks.
Garlic extract 300 mg three times daily has been used with apparent safety for up 8 weeks in children ages 8-18 years (4796). There is insufficient reliable information available about the safety of garlic when used over longer durations or in higher doses.
CHILDREN: POSSIBLY UNSAFE
when raw garlic is used topically.
Raw garlic might cause severe skin irritation when applied topically (585,51210).
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.
Below is general information about the interactions of the known ingredients contained in the product Licorice + Garlic. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Garlic may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
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Theoretically, taking garlic with antidiabetes drugs might increase the risk of hypoglycemia.
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Theoretically, taking garlic with antihypertensive drugs might increase the risk of hypotension.
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Theoretically, garlic might decrease levels and effects of atazanavir.
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In a case report, a patient consuming six stir-fried garlic cloves three times weekly developed suboptimal atazanavir levels and increases in HIV viral load. While the exact cause of this interaction is unclear, there is speculation that garlic might decrease the intestinal absorption of atazanavir or increase its metabolism by inducing cytochrome P450 3A4 (CYP3A4) (88388). Until more is known, advise patients not to consume large amounts of garlic while taking atazanavir.
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Garlic might increase levels of drugs metabolized by CYP2E1.
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Clinical research suggests garlic oil can inhibit the activity of CYP2E1 by 39% (10847). Use garlic oil cautiously in patients taking drugs metabolized by these enzymes.
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Theoretically, garlic products containing allicin might induce intestinal CYP3A4 and inhibit hepatic CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
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Some human research suggests that garlic may induce INTESTINAL CYP3A4, reducing levels of drugs metabolized by this enzyme. This is primarily based on a study showing that taking a specific allicin-containing garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induced CYP3A4 in the gut mucosa (7027,93578). Another study shows that giving docetaxel intravenously, bypassing the CYP3A4 enzymes in the gut mucosa, along with the same specific garlic product for 12 consecutive days, does not affect docetaxel levels (17221). Conversely, there is concern that garlic may inhibit HEPATIC CYP3A4. In a single case report, increased tacrolimus levels and liver injury occurred in a liver transplant patient after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days (96010). Several other studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin (10335,10847,15031,94506).
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Theoretically, garlic might decrease levels of isoniazid.
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Animal research suggests that an aqueous extract of garlic reduces isoniazid levels by about 65%. Garlic reduced the maximum concentration (Cmax) and area under the curve (AUC), but not the half-life, of isoniazid. This suggests that garlic extract might inhibit isoniazid absorption across the intestinal mucosa (15031); however, the exact mechanism of this potential interaction is not known.
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Theoretically, garlic products containing allicin might decrease levels of PIs.
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Protease inhibitors are metabolized by cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4, reducing plasma levels of protease inhibitors. This is primarily based on a study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces levels of saquinavir, a PI, by approximately 50%. It is speculated that the allicin constituent induce CYP3A4 in the gut mucosa (7027,93578). Several studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin (10335,10847,15031,94506).
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Theoretically, garlic containing allicin might decrease levels of saquinavir.
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Saquinavir is a substrate of cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4 and cause subtherapeutic levels of saquinavir. This is primarily based on a pharmacokinetic study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induces CYP3A4 in the gut mucosa (7027,93578). Several pharmacokinetic studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin (10335,10847,15031,94506). Until more is known about this potential interaction, use garlic containing allicin cautiously in patients taking saquinavir.
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Theoretically, taking garlic with sofosbuvir might decrease its effectiveness.
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Animal research in rats shows that giving aged garlic extract 120 mg/kg orally daily for 14 days decreases the area under the concentration time curve (AUC) after a single sofosbuvir dose of 40 mg/kg by 36%, increases the clearance by 63%, and decreases the plasma concentrations at 1 and 8 hours by 35% and 58%, respectively. This interaction is hypothesized to be due to induction of intestinal P-glycoprotein expression by garlic (109524).
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Theoretically, garlic might increase levels of tacrolimus.
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In one case report, a liver transplant patient taking tacrolimus experienced increased tacrolimus levels and liver injury after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days. It is speculated that garlic inhibited hepatic cytochrome P450 3A4 (CYP3A4), which increased plasma levels of tacrolimus (96010).
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Theoretically, garlic might increase the risk of bleeding with warfarin.
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Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time (586,616,1874,3234,4366,4802,4803,51397). In addition, there is a report of two patients who experienced an increase in a previously stabilized international normalized ratio (INR) with concomitant garlic and warfarin use (51228,51631). However, this report has been subsequently debated due to limited clinical information. Other clinical studies have not identified an effect of garlic on INR, warfarin pharmacokinetics, or bleeding risk (15032,16416). More evidence is needed to determine the safety of using garlic with warfarin.
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Theoretically, licorice might reduce the effects of antihypertensive drugs.
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Theoretically, licorice might reduce the effects of cisplatin.
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In animal research, licorice diminished the therapeutic efficacy of cisplatin (59763).
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Theoretically, concomitant use of licorice and corticosteroids might increase the side effects of corticosteroids.
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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).
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Theoretically, licorice might increase levels of drugs metabolized by CYP2B6.
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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.
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Theoretically, licorice might increase levels of drugs metabolized by CYP2C19.
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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.
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Theoretically, licorice might increase levels of drugs metabolized by CYP2C8.
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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.
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Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP2C9.
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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.
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Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP3A4.
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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.
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Theoretically, concomitant use of licorice with digoxin might increase the risk of cardiac toxicity.
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Overuse or misuse of licorice with cardiac glycoside therapy might increase the risk of cardiac toxicity due to potassium loss (10393).
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Theoretically, concomitant use of licorice with diuretic drugs might increase the risk of hypokalemia.
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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).
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Theoretically, licorice might increase or decrease the effects of estrogen therapy.
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Theoretically, loop diuretics might increase the mineralocorticoid effects of licorice.
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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).
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Theoretically, licorice might increase levels of methotrexate.
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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.
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Theoretically, licorice might decrease levels of midazolam.
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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.
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Theoretically, licorice might decrease the absorption of P-glycoprotein substrates.
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In vitro research shows that licorice can increase P-glycoprotein activity (104561).
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Theoretically, licorice might decrease plasma levels and clinical effects of paclitaxel.
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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).
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Theoretically, licorice might decrease plasma levels and clinical effects of warfarin.
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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.
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Below is general information about the adverse effects of the known ingredients contained in the product Licorice + Garlic. 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, garlic is generally well tolerated.
Topically, garlic seems to be well tolerated. Intravenously, there is insufficient reliable information available about adverse effects.
Most Common Adverse Effects:
Orally: Abdominal pain, body odor, flatulence, malodorous breath, and nausea. Allergic reactions in sensitive individuals.
Topically: Burns and dermatitis with fresh garlic.
Serious Adverse Effects (Rare):
Orally: Some case reports raise concerns about increased risk of bleeding with garlic.
Dermatologic
...Orally, garlic may cause pruritus (51316,51474,107239), flushing, and acne (107239).
Oral intake of a specific garlic product containing allicin (Allimax) has been associated with a case of pruritic rash (51474). Enteric-coated garlic tablets standardized to 1.5% allicin have also been associated with a case of pruritus (51316). Garlic has also been associated with a case of superficial pemphigus in a 49-year-old male with type 2 diabetes (51564). Garlic-induced oral ulcers have also been reported (51467).
Topically, garlic may cause contact dermatitis and urticaria (4833,5004,12635,51258,51265,51375,51403,51412,51459,51483)(51511,51512,51530,51616,51617,51618,111769), as well as contact cheilitis (51384). Fresh garlic may be more likely to elicit a reaction than garlic extract. Most reactions have resolved following withdrawal of garlic therapy. In one case report, applying crushed garlic on the neck to help ease a sore throat resulted in an itchy, burning, erythematous lesion in a young female patient. The lesion healed after one week of treatment with topical antibiotics, steroids, and antihistamine ointments (88390). Cases of occupational eczema or dermatitis have been reported in cooks (51303,51210), food handlers (51292), and caterers (51304). According to one case report, dermatitis appeared in chefs exposed to garlic (15033). Treatment with acitretin 25 mg daily or topical psoralen-ultraviolet A (PUVA) for 12 weeks proved effective in mitigating the symptoms. A 34-year-old female with a history of hand dermatitis and paronychia had a worsening of these conditions after peeling raw garlic. She had a positive skin patch test to fresh, raw garlic but not to any other tested allergens, and the conditions resolved when she avoided contact with garlic (105528). Topically, garlic may also cause chemical burns, usually within 12 hours of application. Second- and third-degree chemical burns have been reported in adults, children, and infants exposed to topical garlic, often as an unintended consequence of using garlic medicinally on the skin (585,4832,51226,51230,51252,51281,51377,51418,51468,51495,51536)(51558,51576,51577,88409,96006). A case of painful blisters on the soles of the feet of a 23-year-old Chinese female has been attributed to chemical burns caused by applying crushed raw garlic for 3 hours (51440). Topically, garlic may also cause hyperpigmentation, ulcers, necrotic lesions, facial flushing, and local irritation (4832,15030,51268,51269,108606). In one case report, applying crushed raw garlic to the palatal mucosa for several minutes to relieve mouth pain resulted in a chemical burn that produced a 3 cm necrotic ulcer in an adult female with trigeminal neuralgia (108606).
Gastrointestinal
...Orally, dehydrated garlic preparations or raw garlic may cause malodorous breath (51438,51444), body odor (732,1873,4784,4793,4795,4798,9201,10787,42692,49769)(51269,51316,51467,51602), abdominal pain or fullness, anorexia, diarrhea, constipation, flatulence, belching, heartburn, nausea, unpleasant taste, reflux, and bowel obstruction (1884,6457,6897,9201,49769,51269,51343,51380,51438,51442)(51450,51457,51466,51471,51474,51520,51593,51602,51623,88398)(88405,111766).
Large quantities of garlic may damage the gastrointestinal tract. In one case report, a patient taking garlic for hypertension reported odynophagia and retrosternal pain after taking garlic without any water the previous day. An esophageal lesion 3 cm in length was detected upon endoscopy. The symptoms resolved 3 days after starting a liquid diet and taking lansoprazole 30 mg twice daily and sucralfate four times daily (88389). One case of bowel obstruction was reported in a 66-year-old male who ingested an entire garlic bulb (51525). Esophageal perforation has been reported in at least 17 individuals who consumed entire garlic cloves. In one case the perforation led to mediastinitis and death (102672).
Garlic has also been associated with eosinophilic infiltration of the gastrointestinal tract. In one case report a 42-year-old female presented with symptoms of eosinophilic gastroenteritis, which included pollinosis, asthma, diarrhea, heart burn, peripheral eosinophilia, and urticaria. After stopping use of garlic and sesame, the patient improved (51441). In a case report of eosinophilic esophagitis, garlic was determined to be the causative agent in a patient with long-standing gastrointestinal symptoms. The patient had attempted to treat upper gastrointestinal symptoms as gastrointestinal reflux disease without success for many years. Skin prick testing showed a positive reaction to garlic, of which the patient noted frequent consumption. Marked symptom improvement was noted within 3 weeks of garlic avoidance (88393).
Intravenously, garlic 1 mg/kg of body weight daily diluted into 500 mL saline and administered over 4 hours has been reported to cause abdominal discomfort, vomiting, diarrhea, nausea, anorexia, flatulence, weight loss, and garlicky body odor (51462).
Clinical research suggests that patients with metabolic syndrome taking 1600 mg of powdered garlic by mouth daily for 3 months may experience improved intestinal transit time when compared with placebo, suggesting that garlic powder may reduce symptoms of constipation (110722).
Genitourinary ...Orally, garlic might cause dysuria, hematuria, or polyuria (51438,51450,51467,113618). In one case, an older male with high dietary and supplemental garlic intake at doses of 300-5400 mg daily for 3-4 years developed severe hematuria with clots after undergoing a minimally invasive prostate procedure (113618).
Hematologic
...Oral use of dietary garlic or supplements containing garlic has caused platelet dysfunction, increased fibrinolytic activity, prolonged bleeding time, retrobulbar hemorrhage (bleeding behind the eye) postoperative bleeding, and spinal epidural hematoma (586,587,4801,4802,11325,51397,51473,51491,51532,51534)(51570,51584,51593,51594,113618).
Also, a case of kidney hematoma following extracorporeal shock-wave lithotripsy (SWL) has been reported in a patient with nephrolithiasis who took aged garlic (51630). A case of increased bleeding time that complicated epistaxis management has been reported in a patient taking garlic, aspirin, and milk thistle (51426).
Intravenously, garlic has been associated with the development of thrombophlebitis at the injection site (51462).
Immunologic
...There is a case report of an immediate sensitivity reaction to oral raw garlic, resulting in wheals, in a 31-year-old female.
The patient did not react to cooked garlic, and skin prick tests showed allergy only to raw garlic (96015). Researchers note that at least some allergens in raw garlic are heat labile (88392,96012,96015). This suggests that consuming cooked rather than raw garlic may help avoid this reaction in patients allergic to raw garlic. However, different people react to different allergens in garlic. At least some of these allergens are heat stable (96012). While rare, garlic-induced anaphylaxis has been reported (88392,96012).
Topically, allergic contact dermatitis has been reported in case reports (51406,51498,51510,51519,51560).
Musculoskeletal ...Orally, garlic has been associated with individual cases of gout and low back pain (51474,51467), but it is not clear if these adverse events can be attributed to garlic.
Neurologic/CNS ...Orally, dizziness, insomnia, headaches, diaphoresis, fever, chills, somnolence, increased appetite, euphoria, and weight loss have been reported with garlic (15032,42692,51316,51467,51471,51520). In one case, the smell of garlic was identified as a trigger for migraines in a 32-year-old female. The subject reported fortification spectra along with visual spots for a few seconds followed by instantaneous biparietal, crushing level (10/10) headaches upon exposure to the scent of garlic or onion (88404).
Pulmonary/Respiratory ...Garlic exposure, most notably in occupational settings, may cause asthma and other symptoms such as sneezing, nasal obstruction, rhinorrhea, and sinusitis (40661,51218). A case of minor hemoptysis has been reported for one patient with cystic fibrosis following intake of garlic capsules orally once daily for 8 weeks (51438). A 77-year-old female developed pneumonia related to the intake of one whole black garlic clove daily. The cloves were prepared by heating a whole garlic bulb in a pot for one month. Symptoms included dyspnea and coughing, and test results were positive for lymphocyte-induced stimulation by black garlic and raw garlic. The patient required treatment with oral steroids and was told to avoid garlic (96011).
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).