PEA (palmitoylethanolamide): the body's own inflammation brake in a capsule

Healthy state

Palmitoylethanolamide, PEA for short, is a fatty substance that almost all tissues make themselves, including the gut wall. It is produced on demand from building blocks of the cell membrane, for example when tissue is irritated or injured, and is broken down again quickly. Chemically, PEA is a relative of anandamide, one of the body's own cannabinoids. But it hardly binds to the classic cannabinoid receptors and does not get you high.

Its main target is a switch in the cell nucleus called PPAR-alpha. When it is flipped, immune cells turn down the production of inflammatory messengers. PEA also slows the breakdown of anandamide and so indirectly strengthens its effect. Researchers call this the entourage effect, an effect through companions.

In the gut, the effect on two cell types matters most. Mast cells Mast cells Immune cells beneath the skin and mucous membranes, filled with histamine and other messengers. They raise the alarm in allergies, infections and stress. More in the chapter “Mast cells: alarm cells in the gut, histamine and the disputed MCAS” sit beneath the lining next to nerve endings and release histamine Histamine A messenger substance of the body that is also found in aged and fermented foods. Too much can cause headache, flushing or diarrhoea. More in the chapter “Histamine intolerance: much searched, little proven” and other irritants when alarmed. In the lab, PEA dampens their activation. Glial cells are support cells of the gut's nervous system. When they become overactive, they fuel inflammation. In mice with artificially induced colitis and in tissue samples from people with ulcerative colitis, PEA calmed these glial cells and lowered inflammatory markers. The effect disappeared when PPAR-alpha was blocked.

PEA also seems to help seal the gut wall. In cell cultures and in gut tissue from surgery, it prevented the wall from becoming leakier under inflammatory messengers. In a small randomised human trial, aspirin made the gut wall more permeable, and PEA reduced this increase.

Small amounts of PEA are found in foods such as egg yolk and peanuts. The amounts used in studies are far higher and cannot be reached through food alone. Because PEA barely dissolves in water, it is poorly absorbed. That is why products are often micronised, meaning ground into very fine particles.

Disrupted state: causes and effects

In inflammatory bowel diseases Inflammatory bowel disease Umbrella term for Crohn’s disease and ulcerative colitis: long-term, relapsing inflammation of the gut that needs medical treatment. More in the chapter “Immune system and inflammation”, the PEA system is altered. In the lining of people with active ulcerative colitis and active coeliac disease Coeliac disease An autoimmune disease in which gluten damages the lining of the small intestine. It is diagnosed with a blood test and usually a biopsy while you are still eating gluten. More in the chapter “Lactose, fructose, gluten: making sense of intolerances”, researchers found about twice as much PEA as in healthy people. That looks more like the body trying to counteract than like a deficiency. In irritable bowel syndrome Irritable bowel syndrome Recurring abdominal pain linked to bowel movements, without tests finding another cause. Today it is understood as a disorder of gut–brain interaction. More in the chapter “The gut-brain axis”, one study found more mast cells in the lining and less of a closely related fatty substance (oleoylethanolamide). Whether a lack of PEA causes symptoms has not been shown.

PEA is best studied in irritable bowel syndrome, in combination with polydatin, a plant substance from Japanese knotweed that is also thought to calm mast cells. In a European pilot trial with 54 adults, participants took 200 mg PEA with 20 mg polydatin twice daily or a placebo Placebo A dummy treatment without an active ingredient. Comparing with it shows how much a remedy achieves beyond expectation and chance. for 12 weeks. The number of mast cells in the lining did not change. According to the researchers, pain severity fell markedly more with the product. A later review read the same data more cautiously: the share of people who got clearly better did not differ from placebo.

A second trial with 70 children and teenagers aged 10 to 17 found a clearer result in 2024. After 12 weeks, markedly more children on the combination product had hardly any symptoms left than on placebo, especially in IBS with diarrhoea. Pain intensity and pain days fell, and no side effects were seen. Both trials are small, partly come from the same researchers and did not test PEA alone. Independent confirmation in adults is still missing.

For pain in general the evidence is broader. Two meta-analyses Meta-analysis An analysis that combines the results of several studies. It is only as good as the studies it includes. from 2017 and 2023, each with 8 to 11 trials, found that PEA lowered pain on a 0 to 10 scale by almost 2 points more than the comparison treatment. But the trials varied greatly in condition, dose and duration, almost all had fewer than 100 participants, and some were paid for by manufacturers. Whether the difference is noticeable in daily life is open.

For ulcerative colitis and Crohn's disease there are so far only animal experiments and tissue samples. A first randomised trial Randomised trial A study in which chance decides who gets the treatment and who does not, for comparison. This makes results particularly reliable. with 60 people with ulcerative colitis has been running since 2026; results are not expected before 2028. For mast cell activation syndrome Mast cell activation syndrome (MCAS) A rare condition with repeated attacks caused by mast cell messengers in several organs. The diagnosis needs lab evidence during an attack. More in the chapter “Mast cells: alarm cells in the gut, histamine and the disputed MCAS”, histamine intolerance, small intestinal bacterial overgrowth Small intestinal bacterial overgrowth (SIBO) Too many bacteria in the small intestine, where normally few live. Bloating and diarrhoea are typical; it is usually diagnosed with a breath test. More in the chapter “When the small intestine is too densely colonised” or long Covid we found no human study, even though PEA is often recommended for them.

In the trials PEA was well tolerated; side effects were rare and mostly mild stomach or gut complaints. But so few people have been studied beyond two months that rare side effects cannot be ruled out. In 2018, a Danish food safety institute considered at most 350 mg a day as a supplement to be shown safe for healthy adults. This is not because of observed harm: rats tolerated even very high amounts over 90 days. The institute simply applied the usual safety margins and found too little data for higher amounts. Studies in pregnancy and breastfeeding are missing.

Depending on the country, PEA is sold as a food supplement or as a food for special medical purposes, and it is not a medicine. Products differ in particle size, purity and additives. Whether micronised PEA works better in humans than ordinary PEA has never been compared directly.