Do peppermint oil capsules work for IBS?

If you’ve ever read one of my blogs before you may know that I’m a hypnotherapist who specialises in hypnotherapy for IBS. What, you may ask, has that to do with peppermint oil?  Well, the other day I was giving a free consultation with a potential IBS patient. As we discussed the various treatments he had tried gradually he realised that when he’d been using peppermint oil his symptoms were much improved. Long story short, I never ended up treating him because he went back onto the peppermint capsules. Not my greatest day of business. But it did get me thinking about peppermint oil and wondering do peppermint oil capsules work for IBS?

There is certainly a potential case for peppermint oil benefiting people with IBS. Peppermint oil has been found to have antimicrobial, anti-inflammatory, antioxidant, immunomodulating and anaesthetic properties (1) any one of which could prove beneficial to someone with IBS and possibly the combination even more so. But theoretical benefit is one thing, is there any evidence that it really makes a difference?

Do peppermint oil capsules work for IBS? – latest research 2019

Fortunately for me a team from John Hopkins University investigated this very question just recently (1). The team used a statistical approach known as a meta-analysis. A meta-analysis combines the findings of several randomised controlled trials (RCTs) into one with the aim of averaging out all the peculiarities which inevitably accompany an RCT. The studies they used were carefully selected to exclude anything which looked like it might skew the findings in an unfair way. Specifically, they only used studies which;

1) used peppermint for at least two weeks consistently.

2) where participants had been demonstrated to be free of other relevant organic conditions.

3) had adult populations.

4) where a recognised diagnostic measure of IBS had been used (manning or ROME criteria)

5) Used some form of comparator, such as a placebo.

From a systematic search of the published trials they identified twelve which made the grade. These covered people from eleven different countries over three continents.

Do peppermint oil capsules work for IBS? – Results

They work! The team found that peppermint oil produced a general improvement in IBS symptoms over placebo, and improved abdominal pain.

That is not to say they will work for everyone all the time. In fact, the team identified that the average number of people with IBS who would need to take peppermint capsules for one to experience a significant benefit is three. This figure is over and above placebo effect so typically in a real-world situation you might expect half of people who take it to genuinely benefit. In addition, they found that the risk of adverse events coming from taking peppermint capsules was low. Which means that Peppermint capsules are a relatively cheap and proven approach for people who experience IBS  

Do peppermint oil capsules work for IBS? – Rules for taking peppermint oil

There is a lot of conflicting advice out there and a huge variety of products. If you are going to use peppermint oil for your IBS I recommend you follow these two rules:

1.    Take it daily for minimum of 2 weeks before judging the results

2.    Buy a make with an enteric coating  


1) Weerts, Z. Z. R. M., Masclee, A. A. M., Witteman, B. J. M., Clemens, C. H. M., Winkens, B., Brouwers, J. R. B. J., … & Tack, J. (2019). Efficacy and Safety of Peppermint Oil in a Randomized Double-blind Trial of Patients With Irritable Bowel Syndrome. Gastroenterology.