Supplement
Peppermint Oil + Caraway Oil (enteric-coated combination)
Peppermint oil plus caraway oil is a fixed combination of the two oils in enteric-coated capsules, studied for functional dyspepsia: recurring upper-stomach pain, fullness or bloating with no ulcer or other cause found. A 2023 Cochrane review rated it as probably giving a large improvement in overall symptoms over placebo after 4 weeks (moderate certainty), and placebo trials of 39 to 114 people found less pain and fullness. A 2019 meta-analysis of 5 trials agreed, though one of them tested caraway oil with L-menthol, a different product. Reported side effects were no more frequent than on placebo, while peppermint oil alone brought heartburn in bowel trials. Peppermint oil alone has its own page.
Sources: PMID 37323050; PMID 9006790; PMID 11121917; PMID 28695660; PMID 31827561; PMID 24100754
- Updated
- How we grade
- 15 studies cited
- Best evidence
- Grade A: strong evidence
What the evidence says
- Pooled results: a 2023 Cochrane review covering 27 herbal medicines in 41 trials (4477 people) found that peppermint and caraway oil probably results in a large improvement in global dyspepsia symptoms compared with placebo at four weeks (standardised mean difference -0.87; 2 studies, 210 participants; moderate certainty), increases the improvement rate (risk ratio 1.53; 3 studies, 305 participants) and probably improves quality of life (1 study, 99 participants). Its reference list also holds two trials of a caraway oil and L-menthol capsule, and its summary does not name the trials in this comparison. A 2019 meta-analysis of 5 placebo-controlled trials (578 participants) found global improvement (risk ratio for no improvement 0.59; 3 people treated for each one helped) and less upper-stomach pain (risk ratio 1.61); four of its trials tested the peppermint and caraway oil combination and one, in 95 people, a caraway oil and L-menthol capsule, and the authors judged its evidence of low to very low quality. A 2023 review of the same branded combination pooled 3 dyspepsia trials (249 patients): pain fell (standardised mean difference 0.80) and global improvement was more likely (risk ratio 2.65).
- Placebo trials: in 39 evaluated patients, pain and the doctor's global rating improved more than on placebo after four weeks; in 96 outpatients treated for 28 days, pain fell 40% against 22% on placebo, pressure and fullness 43% against 22%, and 67% against 21% were much or very much improved; and in 114 outpatients treated for 4 weeks, pain scores improved by 7.6 points against 3.4 and discomfort by 3.6 against 1.3, with the combination ahead of placebo at 2 and 4 weeks.
- Against medicines and over longer use: in 118 outpatients, the combination cut pain about as much as the prokinetic drug cisapride (4.62 against 4.60 points over four weeks), an equivalence trial with no placebo; in 213 patients, the enteric-coated capsule and an older enteric-soluble form both reduced pain from the start (by 3.6 and 3.3 points). In 70 patients followed for 11 months on open-label treatment after a placebo trial, those switched from placebo improved towards the results of those already on the combination, and over 90% in both groups were much or very much improved; and in 126 people with abdominal pain or bloating treated for 8 weeks in a single-arm study, symptoms and stool habits improved from baseline. Neither of these last two had a control group.
- A different product: a duodenal-release capsule of caraway oil with L-menthol, the main component of peppermint oil, reduced postprandial distress symptoms against placebo at 24 hours in 95 adults with functional dyspepsia, with global improvement in those with more severe symptoms. In 32 healthy people, an L-menthol and caraway oil combination did not change gastric emptying or stomach pressure but raised hunger when fasting. These results belong to that product, not to the peppermint oil capsule.
Safety and when to see a clinician
- Side effects: in the combination trials adverse events occurred at rates close to placebo (Cochrane risk ratio 1.56, 95% CI 0.69 to 3.53, low certainty; no difference in the 2019 analysis), and in the 96-patient trial burping with a peppermint taste did not occur. In trials of peppermint oil alone for irritable bowel syndrome, adverse events were more frequent than on placebo and heartburn was the commonest, so stop and speak to your doctor if heartburn or reflux appears or gets worse.
- Allergy: caraway contains pan-allergens similar to birch pollen proteins, and people allergic to both birch and mugwort pollen can react to spices such as caraway through cross-reactivity. Anyone with that pollen-spice pattern of allergy should check with an allergy specialist first.
- When to see a doctor: new or lasting indigestion with weight loss, difficulty swallowing, repeated vomiting, black stools or anaemia needs a medical assessment before self-treatment, since these can point to an ulcer, bleeding or cancer.
- Pregnancy and young people: the trials were in outpatients with dyspepsia, and a 2023 review mentions tolerability data from 12 years of age; for children and teenagers the amount should be set by their doctor, and in pregnancy or while nursing, get the maternity team's go-ahead before use.
What peppermint oil + caraway oil (enteric-coated combination) is good for
How we grade →Strong evidence
Dyspepsia Symptoms: Improves
All 2 outcomes ↓
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
AIndigestion
▲ Dyspepsia Symptoms · ▲ Epigastric Pain2 outcomes · 5 studies
Indigestion: all the evidence on its own page
| Grade | Outcome | Effect | Size and studies |
|---|---|---|---|
| A | Dyspepsia SymptomsLarge ImprovementStudied as: Enteric-coated capsule of the fixed combination as studied: 90 mg peppermint oil + 50 mg caraway oil (Menthacarin / Enteroplant), one capsule twice daily for 4 weeks; side effects about as common as placebo in the trials (Cochrane: low certainty); peppermint oil can cause heartburn or belching. Not evidence for peppermint oil or caraway alone.Studies that measured dyspepsia symptoms (5 studies)
| Improves | Large effect · 5 studiesReviewed |
| C | Epigastric PainImprovementStudied as: Enteric-coated capsule of the fixed combination as studied: 90 mg peppermint oil + 50 mg caraway oil (Menthacarin / Enteroplant), one capsule twice daily for 4 weeks; side effects about as common as placebo in the trials (Cochrane: low certainty); peppermint oil can cause heartburn or belching. Not evidence for peppermint oil or caraway alone. A 2019 meta-analysis of five randomised trials (PMID 31827561) rated the evidence low to very low quality because the trials were small.Studies that measured epigastric pain (4 studies)
| Improves | 4 studiesReviewed |
Studies cited
15 studies from PubMed
- Non-Chinese herbal medicines for functional dyspepsia.
- Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia.
- Efficacy and tolerability of a fixed combination of peppermint oil and caraway oil in patients suffering from functional dyspepsia.
- A randomized placebo-controlled trial on the effects of Menthacarin, a proprietary peppermint- and caraway-oil-preparation, on symptoms and quality of life in patients with functional dyspepsia.
- A Combination of Peppermint Oil and Caraway Oil for the Treatment of Functional Dyspepsia: A Systematic Review and Meta-Analysis.
- Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis.
- Menthacarin, a Proprietary Peppermint Oil and Caraway Oil Combination, Improves Multiple Complaints in Patients with Functional Gastrointestinal Disorders: A Systematic Review and Meta-Analysis.
- Treatment of functional dyspepsia with a fixed peppermint oil and caraway oil combination preparation as compared to cisapride. A multicenter, reference-controlled double-blind equivalence study.
- [Peppermint oil-caraway oil fixed combination in non-ulcer dyspepsia--comparison of the effects of enteric preparations].
- Menthacarin for long-term treatment of functional dyspepsia - Results from a clinical trial follow-up.
Show all 15 studies
- Treatment of disorders of gut-brain interaction with peppermint oil and caraway oil combination Menthacarin : A phase IV clinical trial.
- A Novel, Duodenal-Release Formulation of a Combination of Caraway Oil and L-Menthol for the Treatment of Functional Dyspepsia: A Randomized Controlled Trial.
- The combination of L-menthol and caraway oil does not affect gastric function but increases hunger in healthy subjects.
- Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome.
- New allergens from spices in the Apiaceae family: anise Pimpinella anisum L. and caraway Carum carvi L.