Peppermint tea: the gut evidence belongs to the oil

Peppermint has a strong reputation for the gut, and the strong evidence behind it is for oil capsules. In a network meta-analysis of 51 randomized trials in 4644 adults with irritable bowel syndrome, peppermint oil capsules ranked first, with a relative risk of 0.63 (95% CI 0.48 to 0.83) of failing to improve over 4 to 12 weeks. Only 13 of those trials were at low risk of bias. An earlier meta-analysis of 4 trials in 392 adults gave a relative risk of persistent symptoms of 0.43 (95% CI 0.32 to 0.59), and a Cochrane review found a significant benefit for peppermint oil in its subgroup analysis. All of them tested oil. We found no trial of peppermint tea itself in irritable bowel syndrome or indigestion. What the tea does measurably is block iron. Drunk with a bread meal, it cut non-heme iron absorption by 84% compared with water, about as much as black tea, in a single-meal isotope study that was not randomized.

How much is actually in it

• A systematic review of 49 studies found metals in all commonly consumed herbal teas, though most estimated health risks were acceptable. — 49 analytical studies of herbal teas, 2012-2023 (n = 49 studies) Evidence C source
  Over 70% of health risks acceptable; arsenic and lead flagged

What a real portion looks like

• The EU monograph dose for adults is 1.5-3.0 g dried leaf steeped in 3.4-5.1 fl oz (100-150 ml) boiling water, three times a day, for digestive complaints. — Adults and elderly Evidence E source
  1.5-3.0 g leaf per 100-5.1 fl oz (150 ml), 3 times daily

What your body absorbs

• Peppermint tea drunk with a bread meal cut non-heme iron absorption by 84% compared with water, as much as black tea. — Adult volunteers, single test meals, radio-iron erythrocyte incorporation Evidence C source
  -84% iron absorption vs water (black tea -79 to -94%)
• Adding milk did little to blunt the iron-blocking effect of tea and coffee in this absorption study. — Adult volunteers, single test meals Evidence C source
  Little or no change in inhibition with milk
• Observational data from French adults found mean serum ferritin unrelated to black, green or herbal tea drinking. — 954 men aged 52-68 and 1639 women aged 42-68, SU.VI.MAX (n = 2593) Evidence C source
  Mean serum ferritin not related to herbal tea consumption

What it does to your health

• In a crossover RCT of 24 adults, 100 uL peppermint essential oil capsules improved demanding cognitive task scores at 1 and 3 hours. — 24 healthy adults, mean age 25.2, single doses (n = 24) Evidence B source
  Better RVIP performance at 1 h and 3 h; less fatigue at 3 h
• In a single-blind RCT of 25 adults, one 6.8 fl oz (200 mL) cup of peppermint tea brewed 5 minutes improved short-term cognitive scores more than placebo. — 25 adults over 18, convenience sample, single serving (n = 25) Evidence B source
  Greater cognitive improvement and Oxy-Hb rise vs placebo (no pooled size in abstract)

Safety, limits and interactions

• In a crossover RCT of 12 adults, 600 mg peppermint oil raised the blood level (AUC) of the drug felodipine to 140% of that with water. — 12 healthy volunteers, single dose, 4-way crossover (n = 12) Evidence B source
  Felodipine AUC 140% (range 77%-262%) vs water
• In a crossover RCT of 10 healthy women, plain peppermint tea used as placebo caused no reactions, while 75 mg histamine dissolved in it caused symptoms in 5 of 10. — 10 healthy females aged 22-36, hospitalized, 2 challenge days (n = 10) Evidence B source
  0/10 reacted to peppermint tea placebo
• The EU herbal monograph advises people with reflux to avoid peppermint leaf tea and people with gallstones to use it with caution. — People with gastroesophageal reflux or biliary disorders Evidence E source
  Heartburn may increase

What people believe that the data does not support

• In a network meta-analysis of 51 RCTs, peppermint oil capsules ranked first for global IBS symptoms, RR 0.63 for treatment failure at 4-12 weeks. — 4644 adults with IBS, 51 RCTs, 4-12 weeks (n = 4644) Evidence A source
  RR 0.63 (95% CI 0.48-0.83) for failure to improve
• A Cochrane review found antispasmodics helped IBS pain in 58% vs 46% on placebo, with peppermint oil among the agents showing significant benefit. — Patients with IBS over 12 years, 13 RCTs for pain (n = 1392) Evidence A source
  RR 1.32 (95% CI 1.12 to 1.55), NNT 7

Who this works differently for

• In children aged 5 to 18 with recurrent abdominal pain, the RCT evidence for peppermint is for enteric-coated oil capsules, not tea. — Children 5-18 years with recurrent abdominal pain, 10 RCTs Evidence A source
  Decrease in pain outcomes vs control (size not pooled)
• EU regulators do not recommend peppermint leaf tea as a remedy in children under 4 or in pregnancy and breastfeeding, for lack of safety data. — Children under 4; pregnant and lactating women Evidence E source
  Not recommended (insufficient data)

What is still unknown

• The IBS benefit usually credited to peppermint comes from peppermint oil: 4 RCTs in 392 adults gave a relative risk of persistent symptoms of 0.43, and tea itself was not tested. — Adults with IBS, RCTs of at least 1 week (n = 392) Evidence A source
  RR persistent symptoms 0.43 (95% CI 0.32 to 0.59)

The bottom line

That iron effect needs context. In 2593 French adults aged 42 to 68, mean serum ferritin was not related to herbal tea drinking, though the survey was cross-sectional, did not split herbal tea by plant and included only healthy adults. The absorption study also found that milk did little to blunt the iron-blocking effect of tea and coffee, a statement it made for those two drinks and not for peppermint. For thinking, one 6.8 fl oz (200 mL) cup brewed for 5 minutes improved short-term cognitive scores more than a placebo drink in a single-blind trial of 25 adults, a small acute study whose abstract gives no effect size. Capsules of 100 µL peppermint essential oil improved a demanding attention task at 1 and 3 hours in 24 young adults. That is a different product from the cup. Herbal teas in general carry metals. A systematic review of 49 studies found metals in all commonly consumed herbal teas and judged over 70% of the estimated health risks acceptable, with arsenic and lead flagged and peppermint not reported separately. The EU herbal monograph gives adults 1.5 to 3.0 g of dried leaf in 3.4 to 5.1 fl oz (100 to 150 ml) of boiling water, three times a day, as traditional use for digestive complaints. Some people should be careful. The same monograph tells people with reflux to avoid peppermint leaf preparations because heartburn may increase, and people with gallstones or other biliary disorders to use them with caution. It does not recommend the tea for children under 4 or during pregnancy and breastfeeding, because safety data are missing, which is different from harm being shown. In children aged 5 to 18 with recurrent abdominal pain, the trial evidence is for enteric-coated oil capsules. If you take felodipine, 600 mg of peppermint oil raised its blood level to 140% of that with water (range 77% to 262%) in 12 healthy volunteers, from a single dose of concentrated oil rather than tea. In a histamine trial plain peppermint tea served as the placebo, and none of 10 healthy women reacted to it, a trial that was not designed to test reactions to peppermint itself.

Sources

1. pmtea-daily-r8-11 · systematic review
   The results indicated that all commonly consumed herbal teas included metals. None of them meet the requirements of the WHO requirements. However, more than 70% of their health risks are acceptable.
   Biol Trace Elem Res, 2024 · checked 2026-10-01
2. pmtea-daily-r8-15 · agency monograph
   Herbal tea: 1.5-3.0 g of the herbal substance or the comminuted herbal substance in 100-150 ml of boiling water as a herbal infusion 3 times daily
   EMA HMPC, European Union herbal monograph on Mentha x piperita L., folium, Rev. 1 (EMA/HMPC/572705/2014), 2020 · checked 2026-10-01
3. pmtea-daily-r8-01 · controlled absorption study
   Inhibition by black tea was 79-94%, peppermint tea 84%, pennyroyal 73%, cocoa 71%, vervain 59%, lime flower 52% and camomile 47%.
   Br J Nutr, 1999 · checked 2026-10-01
4. pmtea-daily-r8-02 · controlled absorption study
   Adding milk to coffee and tea had little or no influence on their inhibitory nature.
   Br J Nutr, 1999 · checked 2026-10-01
5. pmtea-daily-r8-03 · cross-sectional study
   The mean serum-ferritin concentration was not related to black, green and herbal tea consumption in men, pre- or postmenopausal women.
   Eur J Clin Nutr, 2007 · checked 2026-10-01
6. pmtea-daily-r8-10 · randomized crossover trial
   The highest (100 µL) dose of essential oil improved performance on the cognitively demanding Rapid Visual Information Processing task (RVIP) at 1 h and 3 h post-dose and both doses attenuated fatigue and improved performance of the Serial 3 s subtraction task at 3 h post-dose.
   Nutrients, 2018 · checked 2026-10-01
7. pmtea-daily-r8-12 · randomized controlled trial
   A total of N = 25 individuals, all aged over 18 years, were recruited via convenience sampling...Improvements in cognitive performance were better in the peppermint group.
   Netzler et al., Human Psychopharmacology, 2025 · checked 2026-10-01
8. pmtea-daily-r8-08 · randomized crossover trial
   Grapefruit juice and peppermint oil increased the area under the curve (AUC) values of felodipine to 173% (range, 94%-280%; P <.01) and 140% (range, 77%-262%; P <.05), respectively, of those with water.
   Clin Pharmacol Ther, 2002 · checked 2026-10-01
9. pmtea-daily-r8-09 · randomized crossover trial
   No subject reacted to placebo.
   Allergy Asthma Proc, 2004 · checked 2026-10-01
10. pmtea-daily-r8-13 · agency monograph
    Patients with gastroesophageal reflux (heartburn) should avoid peppermint leaf preparations, because heartburn may increase. Patients with gallstones and any other biliary disorders should be cautious using peppermint leaf preparations.
    EMA HMPC, European Union herbal monograph on Mentha x piperita L., folium, Rev. 1 (EMA/HMPC/572705/2014), 2020 · checked 2026-10-01
11. pmtea-daily-r8-05 · network meta-analysis
    peppermint oil capsules were ranked first for efficacy (RR 0·63, 95% CI 0·48-0·83, P-score 0·84)
    Lancet Gastroenterol Hepatol, 2020 · checked 2026-10-01
12. pmtea-daily-r8-06 · Cochrane review
    There was a beneficial effect for antispasmodics over placebo for improvement of abdominal pain (58% of antispasmodic patients improved compared to 46% of placebo; 13 studies; 1392 patients; RR 1.32; 95% CI 1.12 to 1.55; P < 0.001; NNT = 7)...Subgroup analyses for different types of antispasmodics found statistically significant benefits for cimteropium/ dicyclomine, peppermint oil, pinaverium and trimebutine.
    Cochrane Database Syst Rev, 2011 · checked 2026-10-01
13. pmtea-daily-r8-07 · systematic review
    Evidence for efficacy of treatment of RAP in children was found for therapies that used famotidine, pizotifen, cognitive-behavioral therapy, biofeedback, and peppermint oil enteric-coated capsules.
    Pediatrics, 2003 · checked 2026-10-01
14. pmtea-daily-r8-14 · agency monograph
    The use in children under 4 years of age is not recommended due to a lack of adequate data...In the absence of sufficient data, the use during pregnancy and lactation is not recommended.
    EMA HMPC, European Union herbal monograph on Mentha x piperita L., folium, Rev. 1 (EMA/HMPC/572705/2014), 2020 · checked 2026-10-01
15. pmtea-daily-r8-04 · meta-analysis
    Four trials compared peppermint oil with placebo in 392 patients (0.43, 0.32 to 0.59).
    BMJ, 2008 · checked 2026-10-01