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Western herbalism

PeppermintMentha x piperita

Enteric-coated oil capsules beat placebo for IBS in pooled trials (global symptoms RR 2.39, 12 trials, 835 people); the leaf tea has not been trialed.

Botanical name
Mentha x piperita
Part used
leaf and its essential oil
Also called
Menthae piperitae folium (leaf), Menthae piperitae aetheroleum (oil)
Used in
Western herbalism
Taken for
Cramping and pain, Bloating, Gas, Indigestion
Sold as
capsules, tea, tincture, essential oil

Peppermint, the plant and the part used

Peppermint is a hybrid mint (Mentha x piperita, a cross of water mint and spearmint) grown for its leaves and for the essential oil steam-distilled from them. Two different products carry the name, and the evidence belongs to one of them.

The leaf is dried and steeped as a tea or taken as a powdered or extracted capsule. The European monograph describes the tea as 1.5 to 3.0 g of leaf in 100 to 150 ml of boiling water. The oil is a concentrated liquid whose main constituents include menthol and menthyl acetate. Taken by mouth for the gut, it is sold as capsules with an enteric (acid-resistant) coating, designed to pass the stomach intact and open in the small intestine. The coating exists because the oil released early in the stomach or esophagus tends to cause heartburn.

Nearly all of the human trials below used the coated oil capsule, not the tea. Peppermint also appears in the catalog as isolated menthol and in combination products with caraway oil, which have their own trials.

Traditional uses, in their own terms

Western herbalism

In European herbal practice peppermint leaf tea is a long-standing remedy after meals, for fullness, wind and indigestion. The European Medicines Agency’s herbal committee lists peppermint leaf as a traditional herbal medicine for the symptomatic relief of digestive disorders such as dyspepsia and flatulence, a listing based on long-standing use rather than on trial data. For the oil, the committee’s monograph recognizes a well-established medicinal use for minor spasms of the gastrointestinal tract, flatulence and abdominal pain, especially in people with irritable bowel syndrome, taken in gastro-resistant (acid-resistant) capsules.

Compounds, and what the laboratory says about them

The oil’s constituents include menthol and menthyl acetate. A review of the physiology literature reports that peppermint oil relaxes smooth muscle, possibly by blocking calcium channels or acting on the enteric nervous system, and that it modulates gut sensitivity through transient receptor potential (TRP) channels. It reports antimicrobial and anti-inflammatory activity as well. These are mostly laboratory and small physiology findings, and the review notes the oil affects esophageal, gastric, small bowel, gallbladder and colonic physiology. In a laboratory test, peppermint oil, menthol and menthyl acetate each inhibited the liver enzyme CYP3A4, a route many medicines use (see the interactions section).

Trials in people, with the numbers

Peppermint oil capsules have the largest body of controlled trials of any herbal remedy for irritable bowel syndrome (IBS). A 2014 meta-analysis of enteric-coated oil in 9 trials (726 patients) found a relative risk of 2.23 for global symptom improvement and 2.14 for less abdominal pain. A 2019 meta-analysis of 12 trials (835 patients) reported a relative risk of 2.39 (95% CI 1.93 to 2.97) for global improvement and 1.78 for abdominal pain, with numbers needed to treat of 3 and 4, and no significant difference in adverse events (9.3% against 6.1%). A 2022 analysis of 10 trials (1,030 patients), found a smaller effect: a relative risk of not improving of 0.65 (95% CI 0.43 to 0.98, NNT 4) for global symptoms and 0.76 for pain (NNT 7), more adverse events than placebo (RR 1.57), and very low quality of evidence.

Individual trials are less uniform. In a 190-person trial of 8 weeks of small-intestinal-release oil, 46.8% had an abdominal pain response against 34.4% on placebo, a difference that was not significant (P = 0.170), though secondary measures of pain, discomfort and severity did favor the oil. A 72-person trial of a sustained-release formulation found a 40% fall in total IBS symptom score against 24.3% on placebo (P = 0.0246). In 42 children with IBS, 75% of those on oil capsules had less severe pain after 2 weeks.

A fixed combination of peppermint and caraway oil has its own evidence for functional dyspepsia: 5 trials (578 participants) found a relative risk of 0.59 for failing to improve. We could not find a randomized trial of peppermint leaf tea for gut symptoms, so the tea rests on traditional use.

StudyDoseWhat it found
Meta-analysis of 12 randomized trials in IBS, 835 patients PMID 30654773Enteric-coated oil capsulesGlobal symptoms RR 2.39 (95% CI 1.93 to 2.97), pain RR 1.78; adverse events 9.3% vs 6.1%, not significant
Meta-analysis of 10 randomized trials in IBS, 1,030 patients PMID 35942669Peppermint oil capsulesNot improving RR 0.65 for global symptoms (NNT 4), 0.76 for pain (NNT 7); more adverse events (RR 1.57); very low quality
Meta-analysis of 9 randomized trials in IBS, 726 patients PMID 24100754Enteric-coated oil capsules, at least 2 weeksGlobal improvement RR 2.23; less abdominal pain RR 2.14; heartburn the most common adverse event
Randomized trial, 190 adults with IBS, 8 weeks PMID 31470006182 mg small-intestinal-release oilPain response 46.8% vs 34.4% placebo (P = 0.170, not significant); secondary pain and severity scores improved
Randomized trial, 72 adults with IBS-M or IBS-D, 4 weeks PMID 26319955Sustained-release oil, three times dailyTotal IBS symptom score down 40% vs 24.3% on placebo (P = 0.0246)
Meta-analysis of 5 trials of peppermint plus caraway oil in functional dyspepsia, 578 people PMID 31827561Fixed peppermint and caraway oil combinationNot improving RR 0.59 (95% CI 0.49 to 0.71), NNT 3; epigastric pain RR 1.61

The doses on record

For IBS, the trials used coated oil capsules: 182 mg per dose for 8 weeks in the 190-person trial, and a sustained-release product three times daily for 4 weeks in another. The European monograph’s well-established use gives 0.2 to 0.4 ml of oil in gastro-resistant capsules, 0.6 to 1.2 ml a day divided into two or three doses, swallowed whole 30 minutes before meals, usually for one or two weeks and up to 3 months.

For the leaf, the monograph’s traditional use is a tea of 1.5 to 3.0 g of leaf in 100 to 150 ml of boiling water up to three times daily for adults, and 1.0 to 2.0 g for children 4 to 11.

None of this is a dose recommendation. It is what the literature used, set down so a label can be compared with it; a pharmacist or clinician decides what applies to you.

The safety record

In trials of the oil, heartburn, perianal burning, blurred vision, dry mouth, nausea and vomiting were frequent, according to the European monograph; menthol-smelling urine and stools have been seen. The pooled analyses disagree on whether adverse events outnumber placebo (RR 1.57 in the 2022 analysis, not significant in 2019). Capsules opened early, by chewing or by antacids, can irritate the mouth and esophagus. The monograph lists people with liver disease, bile duct inflammation, achlorhydria and gallstones among those the oil is contraindicated for, and says people with heartburn or hiatal hernia sometimes get worse. Leaf preparations carry the same reflux warning, with caution for gallstones.

Safety in pregnancy and breastfeeding has not been established for either, and the monograph advises against the oil under 8 and the leaf under 4 years of age. Allergic reactions to menthol are reported.

Medicines it can interact with

Peppermint oil inhibited the liver enzyme CYP3A4 in the laboratory, and in a 4-way crossover of 12 healthy volunteers, 600 mg of oil raised the blood exposure (AUC) of the blood-pressure drug felodipine to 140% of the water control (range 77% to 262%). Other medicines cleared by CYP3A4 could in principle be affected, though that has not been tested drug by drug. The European monograph adds a mechanical interaction: food or antacids taken at the same time can release a coated capsule early, and acid reducers (histamine-2 blockers and proton pump inhibitors) can dissolve the coating prematurely. It reports no interactions for the leaf. The catalog’s own drug rules are listed automatically on this page.

The interaction rules the quiz applies to peppermint

These are the medicines the quiz pairs with a caution or an exclusion for this herb, taken from published interaction references:

Where peppermint turns up in the catalog

Peppermint appears on the labels below, alone or inside a blend; each product page gives the printed amount, the evidence for that product and the review picture.

Zenwise Digestive Enzymes 4.4 out of 5 from 67,600 ratings from Amazon · $0.33 a day Twinings Pure Peppermint Herbal Tea 4.7 out of 5 from 14,239 ratings from Amazon · $0.21 a day Physician's CHOICE Digestive Enzymes, Multi Enzymes 4.3 out of 5 from 8,980 ratings from Amazon · $0.34 a day HUM Nutrition Flatter Me Digestive Enzymes 4.1 out of 5 from 8,951 ratings from Amazon · $0.29 a day Amazing Grass Greens Blend Superfood, The Original 4.7 out of 5 from 6,672 ratings from iHerb · $0.89 a day Almape Papaya Seeds Gut Reset Formula 4.82 out of 5 from 6,379 ratings from tryalmape.com · $1.13 a day Calming Blends Diverticulitis Tea 4.5 out of 5 from 4,259 ratings from Amazon · $0.53 per cup; the pouch directs two to three cups a day Traditional Medicinals Organic Peppermint Tea 4.7 out of 5 from 3,922 ratings from Amazon · $0.44 a day FDgard Caraway Oil and L-Menthol Capsules 4.5 out of 5 from 3,144 ratings from Amazon · $3.00 a day Yogi Lemon Ginger Tea 4.7 out of 5 from 3,114 ratings from Amazon · $0.23 per cup on Amazon ($3.68 for 16 bags); $0.31 on iHerb and $0.44 for a single box on the brand’s site Atrantil Polyphenol Blend Capsules 4.3 out of 5 from 1,993 ratings from Amazon · $2.66 a day Traditional Medicinals Organic Triple Mint Daily Probiotic Tea 4.8 out of 5 from 1,976 ratings from Amazon · $0.44 per cup on iHerb, $0.37 on Amazon; the brand directs up to three cups a day

19 more entries list it; the full catalog is grouped by the job each product does.

From the herb to a product that fits you

The quiz weighs your symptoms and medicines against every product researched here, peppermint products included, and shows its working.

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Read next

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Questions people ask

Does peppermint oil help IBS?

Pooled analyses of randomized trials found it beat placebo for global symptoms and abdominal pain, with relative risks of 2.39 and 1.78 in the largest-effect analysis. The newest analysis (10 trials, 1,030 patients) found a smaller effect and called the evidence very low quality. A single 190-person trial missed its main pain target, though secondary measures favored the oil.

Is peppermint tea the same as peppermint oil capsules?

No. Nearly all the IBS trials used enteric-coated oil capsules, a concentrated dose delivered to the small intestine. We could not find a randomized trial of the leaf tea for gut symptoms, so its use rests on tradition, and the European monograph gives it as a traditional herbal medicine.

Why are the capsules enteric-coated?

The coating keeps the oil from releasing in the stomach or esophagus, where it can cause heartburn. The European monograph says capsules should be swallowed whole, and that food, antacids, histamine-2 blockers and proton pump inhibitors can dissolve the coating early.

Can peppermint make reflux worse?

The European monograph says people with heartburn or hiatal hernia sometimes get worse on peppermint oil, and that people with reflux should avoid peppermint leaf preparations because heartburn may increase. Heartburn was also the most common side effect in the IBS meta-analysis.

Is peppermint safe in children?

In a 42-child trial, enteric-coated oil reduced pain severity in 75% after 2 weeks. The European monograph does not advise the oil under age 8 or the leaf under age 4, citing a lack of safety data. The monograph's non-gut uses of the oil are contraindicated under age 2 because menthol can cause reflex apnea.

Sources