There are a lot of options that are worth considering for the management of IBS symptoms, including things like bloating. And honestly, a lot of these options are probably more effective than peppermint oil too. But peppermint oil is probably the easiest of all these options and seems to be so consistently effective for such little effort that it is worth looking into.
What is the Mechanism?
The main way it appears to work is through a muscle relaxant effect on the digestive tract. Peppermint oil has an anti-spasmodic effect.
With IBS, the nerves of the large intestine seem to be overly sensitive which is part of what causes pain. The muscles often overreact which contributes to overall symptoms.
Peppermint oil contains menthol. And menthol appears to reduce that pain, relax those muscles, and reduce any cramping. This alone seems to explain a lot of benefits.
The relaxation is likely caused by menthol blocking calcium channels and serotonin receptors in the gut.
This relaxation could also allow trapped gas to pass through the digestive system. This obviously could help reduce bloating.
There is also a way that it could theoretically help reduce constipation since excess gas could arguably compact faecal matter making it harder to pass. Then constipation would lead to an increase in gas and bloating as well.
In addition to this, there are some antimicrobial, anti-inflammatory and anaesthetic properties of peppermint oil that could potentially contribute to IBS management too.
How Effective is It?
As a starting point, peppermint oil likely does not make any direct difference for diarrhoea.
It does seem to help for bloating, gas and constipation though.
A 2019 meta-analysis that included all the current research on peppermint oil and IBS showed that IBS symptoms became 44% less common for those in the peppermint oil group, in comparison to placebo.
This is a huge win for something that is so easy. A lot of people put a lot more effort in for less reward than that.
It is not magical though. Not everybody seems to get huge benefits from it. There is even a randomised controlled trial with 190 participants that concluded that it did not significantly reduce abdominal pain.
Obviously, that is counter to the premise of this entire article. The overall weight of the evidence points towards it being beneficial for symptoms like IBS related pain. But I wanted to mention this study to highlight that not everything is 100% positive and there is always the chance you do not get noticeable benefit from it.
The other aspect worth mentioning is that it is a short-term effect. Taking peppermint oil does not address the overall condition.
Research indicates that symptoms typically return when peppermint oil usage is discontinued for two weeks or more. This is a bit of a no-brainer though. The purpose is to reduce bloating and IBS symptoms while you are using it. The mechanism does not really make it look like there would be any long-term benefits when you stop.
Potential Side Effects
The 2019 meta-analysis referred to earlier concluded that peppermint oil was safe and that adverse effects were no more common than in the placebo groups.
But an earlier meta-analysis from 2014 highlighted that reflux (heartburn) is a side effect that is reported every now and then.
This has been reported by others as well and it makes sense. Peppermint oil relaxes muscles between the oesophagus and the stomach, which allows acid to move up from the stomach more easily.
For people who have a lot of issues with reflux, it might not be worth having peppermint oil.
Outside of that, some other rarer side effects have included nausea, headache, mouth sores and flushing.
Dosage and how to Use
Adults: 0.2ml to 0.4ml of peppermint oil 3 times a day, 30-60 minutes before eating.
Children aged 8 and up: 0.1ml to 0.2ml of peppermint oil 3 times a day, 30-60 minutes before eating.
This looks slightly confusing, but if you just google peppermint oil capsules, you will notice that a lot of them naturally line up with the above dosing guidelines.
Beyond that, you want to make sure that the capsules have enteric coatings and that you swallow them instead of chewing them. This guarantees it does not dissolve too early. Reported the reflux symptoms are mostly explained by people chewing their tablets instead of swallowing.
Would Peppermint Tea Work?
There is no downside to having peppermint tea, but it probably does not really help IBS symptoms.
Arguably having a hot beverage without caffeine or anything that could stimulate symptoms might make you feel a little better. But peppermint tea itself is not doing anything special.
Other Options to Consider
As mentioned in the intro, there are HEAPS of other options to consider.
What if certain FODMAPs are causing your symptoms? Dietary adjustments based on that would be more helpful in that case.
Lactose intolerance is another option that a lot of people are already aware of. It is worth considering and figuring out whether or not it is relevant for your symptoms and situation too if you have not already done that.
Sometimes food chemicals could contribute to your symptoms. This is a less commonly explored route with far less research, but it could play a role.
Bloating and pain could also be related to constipation. If constipation is an issue, there are other dietary aspects you would want to focus on too.
And other aspects contributing to IBS such as stress and anxiety often are worth addressing too.
All of that stuff and more is beyond the scope of this blog post. But I just wanted to add those in so that there is stuff to consider if the peppermint oil does not get the results, you are looking for.
Peppermint oil is worth a try if you have IBS symptoms including pain, bloating, gas and constipation.
Even if you were not going to do the full protocol 3x per day, it is still worth trialling on a lower frequency if desired.
It is not magical, and it is not guaranteed to solve all symptoms. But it is a relatively easy option to implement that could be helpful.