Search for palmitoylethanolamide and you will find the same handful of studies cited over and over, usually with the findings rounded up and the caveats left out. Sometimes the same paper is listed twice, under two different links, which makes the evidence base look twice as large as it is.
This article does the opposite. Here is what the published clinical research on PEA and chronic pain actually reports, including the parts that are inconvenient.
What PEA is
Palmitoylethanolamide is a fatty acid amide your body produces on its own. It belongs to a family of compounds called N-acylethanolamines, and levels of it rise in tissue during inflammation and injury, which is what first drew research interest to it.
It is not a plant extract, not a cannabinoid, and not a prescription medicine. In Australia it is sold as a complementary medicine.
How it is thought to work
The most studied mechanism is activation of PPAR-alpha (peroxisome proliferator-activated receptor alpha), a receptor in the cell nucleus involved in regulating inflammatory gene expression. PEA has also been studied for its effects on mast cells and glial cells, which play a part in how pain signals are amplified.
Worth being clear: mechanism is not outcome. A plausible pathway explains how something might work. It does not establish that it does. For that you need trials.
What the trials report
There are four distinct pieces of published work that most PEA articles draw on.
1. The 2023 meta-analysis: 11 trials, 774 patients
Lang-Illievich and colleagues pooled 11 double-blind randomised controlled trials of PEA in chronic pain, covering 774 patients (383 on PEA, 391 on placebo or an active comparator).
Their conclusion, verbatim: "Our meta-analysis of double-blind randomized controlled trials reports a pooled effect favoring PEA over placebo or active comparators in the analgesic treatment of chronic pain." The pooled standardised mean difference was 1.68 (95% CI 1.05 to 2.31, p = 0.00001).
This is the most useful single source on PEA, and it comes with serious caveats that the authors state themselves. Those are set out further down.
2. The 2025 meta-analysis: 18 trials, 1,196 patients
Vina and Lopez-Moreno ran a larger systematic review and meta-analysis covering 18 randomised trials and 1,196 patients, published in Nutrition Reviews. They report reductions in pain scores and improvements in quality of life, with effects appearing around the four to six week mark.
One line in that paper describes PEA as a promising alternative to chronic opioid analgesics. The data presented in the abstract do not include any comparison against opioids, so that particular framing goes further than the analysis shows.
3. The 2022 crossover trial: 14 healthy volunteers
This is the study most often cited as proof that PEA helps chronic pain. It does not show that, because it did not study anyone with chronic pain.
It was a randomised, double-blind, placebo-controlled crossover trial in 14 healthy volunteers, who took 400 mg of PEA three times daily for 28 days. It used experimental pain models to measure changes in pain threshold and sensitisation. The authors concluded that PEA has clinically relevant analgesic properties, acting on both peripheral and central mechanisms.
That is a genuine and interesting finding about mechanism in healthy people. It is not evidence of benefit for someone with sciatica or fibromyalgia, and it should not be presented as such.
A note on double counting. This study appears on many websites twice, once as a PubMed link and once as a PubMed Central link. They are the same paper. PubMed Central simply hosts the free full text. If you see a reference list where those two entries are numbered separately, the evidence base is one study smaller than it looks.
4. The 2025 narrative review
Varrassi and colleagues published a review in Pain and Therapy surveying roughly 15 years of PEA publications and discussing its pharmacology and potential use in neuropathic and mixed pain.
This is a narrative review, not a systematic one. It is a useful map of the field and a good reading list. It is not independent evidence that PEA works, and it should not be counted alongside the meta-analyses as though it were.
What the evidence does not show
This is the part usually left out, and it comes from the trial authors themselves.
- The results vary enormously between studies. The 2023 meta-analysis reported heterogeneity of I-squared = 93%. Anything above about 75% is considered high. It means the individual trials disagreed with each other to a degree that makes a single pooled number hard to interpret.
- The trials are small. In the 2023 analysis, all but one enrolled fewer than 100 patients. Small trials tend to overstate effect sizes.
- Statistical significance is not the same as a difference you would feel. The 2023 authors acknowledge directly that the statistical benefit may not translate into a clinically meaningful one for an individual patient.
- Industry involvement. Of the 11 trials in the 2023 analysis, two were company funded and two others had the medication supplied by a manufacturer. None of the included studies reported author financial disclosures.
- Doses and formulations vary widely. The authors describe highly heterogeneous PEA dosages, dosing intervals and treatment courses. Micronised, ultra-micronised and standard PEA are not interchangeable in the literature, and trials have used anywhere from 300 mg to 1,200 mg per day.
- There is little long-term data. Most trials run for weeks, not years.
None of this means PEA does not work. It means the honest summary is promising, with real limitations in the evidence base, rather than clinically proven.
Safety and tolerability
This is the most consistent finding across the literature. The 2023 meta-analysis found reported side effects were essentially negligible, and tolerability is reported as good across trials. Where side effects are reported at all, they tend to be mild and gastrointestinal.
That said, well tolerated in trials is not the same as safe for everyone. If you are pregnant or breastfeeding, taking other medicines, or managing a diagnosed condition, talk to your GP or pharmacist before starting any supplement.
Doses used in research
Published trials have generally used between 300 mg and 1,200 mg per day, often split across two or three doses. The 2022 crossover trial used 1,200 mg daily, as 400 mg three times a day. Where benefit has been reported, it has usually taken around four to six weeks to appear rather than days.
The bottom line
The case for PEA in chronic pain rests on two meta-analyses of mostly small trials, which agree on direction but disagree considerably on magnitude, and which the authors themselves hedge. The safety signal is reassuring. The efficacy signal is real but soft.
If you are considering PEA, that is a reasonable basis for a conversation with your pharmacist or GP about whether trying it makes sense alongside what you are already doing. It is not a reason to stop anything that is working for you.
About our product
Relieve Therapeutics PEA Capsules contain 600 mg of ultra-micronised palmitoylethanolamide per two-capsule serve, with quercetin and luteolin. Manufactured in Australia. Full ingredient and dosage information is on the product page.
Important
This article is general information about published research. It is not medical advice and not a recommendation to treat any condition. Always read the label and follow the directions for use. If symptoms persist, talk to your health professional.
References
- Lang-Illievich K, Klivinyi C, Lasser C, et al. Palmitoylethanolamide in the Treatment of Chronic Pain: A Systematic Review and Meta-Analysis of Double-Blind Randomized Controlled Trials. Nutrients. 2023;15(6):1350. Read it
- Vina I, Lopez-Moreno M. Meta-Analysis of Palmitoylethanolamide in Pain Management: Addressing Literature Gaps and Enhancing Understanding. Nutrition Reviews. 2025;83(7):e1604-e1618. Read it
- Lang-Illievich K, Klivinyi C, Rumpold-Seitlinger G, Dorn C, Bornemann-Cimenti H. The Effect of Palmitoylethanolamide on Pain Intensity, Central and Peripheral Sensitization: A Randomized, Double-Blinded, Placebo-Controlled Crossover Trial. Nutrients. 2022;14(19):4084. Read it
- Varrassi G, et al. A Decades-Long Journey of Palmitoylethanolamide (PEA) for Chronic Neuropathic Pain Management: A Comprehensive Narrative Review. Pain and Therapy. 2025;14(1):81-101. Read it