Peppermint

We evaluated 146 human studies on Peppermint, including 55 randomised controlled trials and 17 meta-analyses or systematic reviews; the controlled studies include 4,562 participants in total. As of 24 October 2026.

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1. What Is Peppermint? Occurrence, Origin and Forms

Peppermint is a cultivated mint species in the Lamiaceae family. Its leaves and the essential oil obtained from them are used above all. Traditionally it serves as a tea and as an oil, among other things for digestive complaints and for external application.

Peppermint grows in temperate climates and is cultivated worldwide in gardens and in field cultivation. The leaves and the essential oil of the plant are used.

The essential oil is produced by steam distillation of the leaves; for tea the leaves are dried. Studies examine above all tea, essential oil, enteric-coated capsules and leaf extracts.

Forms and Preparations Studied

• Peppermint tea (infusion of dried leaves)
• Peppermint essential oil
• Enteric-coated peppermint oil capsules
• Peppermint leaf extract
• Topical preparation (gel or solution)

Not covered on this page:

• Other mint species such as spearmint (Mentha spicata)
• Isolated menthol as a single substance
• Other Lamiaceae such as lemon balm or sage
• Peppermint flavourings without peppermint constituents

2. What Does Peppermint Do? Results by Area

How to read the table: counted are human studies whose results concern the area. “High” means at least one meta-analysis and two controlled studies showing improvement, or at least three controlled studies of which three quarters show improvement, with at least 300 participants in total. “Moderate” means at least two controlled studies showing improvement, as a majority, or one meta-analysis alongside controlled studies. “Low” means one controlled study showing improvement. Where an area has no controlled study, the strength of evidence is at most “low” (result “reviews only” or “observational data only”). Everything else is “unclear”. A study counts as showing improvement when at least half of its outcomes in this area improved. Reviews of combination products do not count as meta-analyses; results that only describe side effects or shares of users do not count as an effect. The same study is counted only once.

3. What the Studies Show in Detail

Peppermint and Nausea: Human Studies

After operations, inhaled essential peppermint oil reduced nausea more than the control in several randomized controlled trials, for example after heart, cervical spine and thyroid operations 485773. In breast cancer patients undergoing chemotherapy, ingested peppermint extract drops relieved nausea, vomiting and loss of appetite more than water 44. Nausea and vomiting also occurred less often in randomized controlled trials 374857. The need for anti-nausea medication decreased in randomized controlled trials after cervical spine operations and after knee replacement 4872. A meta-analysis on inhalation of peppermint oil found less postoperative nausea, reduced symptoms in pregnancy-related nausea and a reduction in symptoms in chemotherapy-induced nausea 12. In pregnant women with nausea, inhaled peppermint oil did not relieve symptoms more than placebo 58. After knee replacement, nausea severity remained the same with peppermint scent as with saline solution 72. Peppermint drops taken before a nasal operation lowered the frequency of nausea, but not of vomiting 45. For peppermint tea or enteric-coated capsules, there is no separate controlled test in this area.

Further studies in this area: 39 41 44 45 48 49 57 58 66 72 73 80 85 87 99 111 132 137

Peppermint and Irritable Bowel Syndrome: Human Studies

In irritable bowel syndrome, peppermint oil, mostly in enteric-coated capsules, improved overall symptoms more than placebo in several meta-analyses 34568. A randomized controlled trial with a peppermint oil released in the small intestine confirmed this for the total symptom score 50. Abdominal pain also improved more than with placebo in several meta-analyses 345. In children with functional abdominal pain, a peppermint oil capsule relieved the duration, frequency and intensity of pain more than placebo 36. This is contrasted by randomized controlled trials: in children with irritable bowel syndrome, peppermint oil was not more effective than placebo 22. In adults, it missed the primary endpoints, but improved abdominal pain, discomfort and severity as secondary endpoints 24. The evidence is strong, but the individual studies are inconsistent; mainly capsules were tested, not tea, and in children the results are contradictory 2236.

Further studies in this area: 24 26 36 50 82 88 89 90 106 107 109 110 111 112 113 114 115 117 119 121 122 123 128 129 130 132 133 134 136 138 139 140 141 142

Peppermint, Cognition and Alertness: Human Studies

For cognition and alertness, a randomized controlled trial with peppermint tea shows that cognitive performance in a computer-based test battery improved more in healthy adults than with placebo 64. A systematic review on essential peppermint oil as a scent comes to no clear result 13. The evidence is moderate: there are only a few small controlled studies with different forms (tea, essential oil as a scent); it is open how these act with longer use or in people with cognitive impairment.

Peppermint, Headache and Migraine: Human Studies

The controlled trials in this area concern migraine and chronic headaches in adolescents, not tension-type headache in the narrower sense. In adults with migraine, peppermint oil nasal drops in a randomized controlled trial relieved headaches more than placebo and similarly to lidocaine drops 35. In adolescents with chronic headaches, a foot bath with peppermint oil did not relieve pain more than a foot bath without oil 62. The strength of evidence is low; above all, it is open how peppermint oil acts in tension-type headache.

Peppermint and Physical Performance: Human Studies

In recreational runners, essential peppermint oil in water in a randomized controlled trial prolonged running time to exhaustion compared with placebo 67. In healthy participants, however, peak oxygen uptake and endurance time remained unchanged after several days of intake 68. The strength of evidence is low, especially since the groups with 14 and 7 participants were small and the tested form was the essential oil, not tea, extract or enteric-coated capsules. An uncontrolled study with before-and-after comparison reports better endurance time and performance after essential peppermint oil in mineral water, but without a control group it cannot show a causal relationship 93. Whether peppermint oil reliably prolongs endurance must be clarified by larger studies.

Peppermint and Functional Dyspepsia: Human Studies

For functional dyspepsia, peppermint has so far been tested mainly in fixed mixtures with caraway oil or other medicinal plants, whose effect cannot be attributed to peppermint alone. One randomized controlled trial with essential peppermint oil alone involved ventilated intensive care patients with enteral nutrition and showed a reduced gastric residual volume, not the digestive complaints themselves 56. The effect of peppermint tea and of essential peppermint oil without caraway in functional dyspepsia remains open.

Further studies in this area: 131 132

Peppermint, Respiratory Tract and Common Cold Symptoms: Human Studies

For respiratory tract and cold complaints, the randomized controlled trial with nebulized essential peppermint oil in healthy participants shows no difference in forced vital capacity, peak expiratory flow, and FEV1/FVC ratio compared with eucalyptus oil, rosemary oil, or no treatment 38. A small study without a control group reports improvements in forced vital capacity, peak expiratory flow, and peak inspiratory flow after mineral water with essential peppermint oil, but this design does not allow causal attribution 93.

Peppermint: Further Outcomes in Studies

Inhaled essential peppermint oil relieved pain more than the control, for example after joint replacement and disc surgery and during placement of a venous catheter in cardiac patients 254651. Before injections at the dentist, children with peppermint oil on the mucosa felt less pain than with lidocaine gel or ice 27. In dialysis patients, peppermint gel reduced puncture pain compared with usual care, similar to a cold pack 43. In menstrual pain, peppermint capsules relieved pain similarly to mefenamic acid, but additional painkillers were taken more often 30. Anxiety also decreased more under inhaled peppermint oil than in the control group, for example after operations and in acute coronary syndrome 2537515370. During placement of a venous catheter, no difference was shown for anxiety 46, and in children before dental treatment, peppermint scent acted more weakly than chamomile and lavender 42. The robustness is overall high, but it is based predominantly on small, sometimes non-blinded studies with short follow-up; results apply in each case to the tested form, such as inhalation, topical preparation or enteric-coated capsule, and are not interchangeable.

Further studies in this area: 19 23 25 27 28 29 30 31 32 33 37 41 42 43 44 45 46 47 48 51 52 53 54 55 59 60 61 62 63 64 65 69 70 71 72 73 74 75 76 77 78 79 81 83 84 86 87 91 92 93 94 95 96 97 98 99 101 102 103 105 108 111 118 120 122 125 126 127 128 132 135

4. How Is Peppermint Dosed? Preparation, Dose and Duration in Studies

The studies mainly tested inhaled or ingested essential peppermint oil, enteric-coated capsules and peppermint extract. Peppermint tea was tested in one controlled trial on cognition. Some studies investigated mixtures with other essential oils or plant extracts, whose results cannot be attributed to peppermint alone. Externally, peppermint oil was tested as a gel on the skin and on the oral mucosa 2743.

5. Is Peppermint Safe? Side Effects in Studies

The side effects were mostly mild and temporary, most commonly heartburn 5. Two meta-analyses found more adverse events with peppermint oil 36, another found no confirmed difference 4. In several controlled trials, peppermint oil was well tolerated, sometimes with no differences from placebo 450.

6. What Remains Open: Limits of the Evidence

• Many studies tested combination products with other active ingredients, so the finding cannot be attributed to peppermint alone.
• Peppermint tea has so far been tested in a controlled way only for cognition; studies on digestion and nausea are still pending.
• The participant numbers of many studies are small, and follow-up is usually short.
• External application and ingestion were investigated separately and are not interchangeable.
• Long-term studies are still pending, and in children with abdominal pain the results are contradictory 2236.

7. Bottom Line: What Is Established About Peppermint

Peppermint has been studied as tea, essential oil, enteric-coated capsules and extract. Nausea and irritable bowel are the best studied: after operations, inhaled peppermint oil relieved nausea more than the control 485773. For irritable bowel, peppermint oil capsules outperformed placebo for overall symptoms and abdominal pain in several meta-analyses 345. For endurance, two small studies contradict each other 6768; for migraine, peppermint oil nasal drops relieved headache more than placebo 35. For cognition and alertness, one randomized controlled trial with peppermint tea found better scores in healthy adults 64.

The side effects were mostly mild and temporary, most commonly heartburn 5; several meta-analyses found more adverse events with peppermint oil than with placebo 356. Overall, the data are broad, but many studies tested mixtures and small groups, and peppermint tea was not tested in a controlled way in most areas.