Oleoylethanolamide (OEA)
Summary
Oleoylethanolamide is a gut-made lipid that reduced food intake in rodents. A 2025 meta-analysis of 10 small trials, mostly from Iran, found modest falls in weight, waist, triglycerides, glucose and inflammatory markers. A 52-veteran trial found less fatigue. Evidence is short-term, at 125–400 mg/day.
Key facts
- An endocannabinoid-like lipid (oleic acid + ethanolamine) produced in the small intestine after fat intake[6]
- 10 RCTs (11 arms): improvements in weight, BMI, waist, fat mass, triglycerides, fasting glucose, insulin, CRP and TNF-α; no change in LDL, HDL, total cholesterol, HbA1c or fat-free mass[1]
- 52 veterans with Gulf War illness: 200 mg twice daily for 10 weeks reduced fatigue and improved mood vs placebo[4]
- 3 graded human outcomes on this page
- October 13, 2026
How it works
ProposedIn rodents, OEA activates the nuclear receptor PPAR-α, which reduced feeding and body weight and increased fat breakdown. A non-randomized (fixed-sequence), single-blind crossover study found a single 300 mg dose raised post-meal GLP-1 and GIP responses. Whether these drive the trial results is unproven.[6][5]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| PCOS | Grade D | Improved | RCT · n = 90 · 2024 | 1 row |
| Lipids | Grade D | Mixed | RCT · n = 60 · 2024 | 1 row |
| Fatigue | Grade D | Improved | RCT · n = 52 · 2026 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Glycemic, inflammatory and oxidative markers in PCOS | Improved | Grade D | RCT · n = 90 · 2024 Women with polycystic ovary syndrome Form: OEA supplement vs wheat-flour placebo · Dose: 125 mg/day · Duration: 8 weeks Fasting glucose, insulin resistance, MDA, CRP, TNF-α and anti-Müllerian hormone fell and total antioxidant capacity rose vs placebo. | 38778429 (opens PubMed)Source [3] |
| Triglycerides and fasting glucose in obesity | Mixed | Grade D | RCT · n = 60 · 2024 Healthy adults with obesity (Iran) Form: OEA capsules · Dose: 125 mg twice daily (250 mg/day) · Duration: 8 weeks Triglycerides fell vs placebo (p=0.044 after adjustment); fasting glucose, other lipids and food-group intake did not change significantly. | 39379951 (opens PubMed)Source [2] |
| Fatigue and mood in Gulf War illness | Improved | Grade D | RCT · n = 52 · 2026 Veterans with Gulf War illness, mean age 59, 94% men Form: OEA · Dose: 200 mg twice daily (400 mg/day) · Duration: 10 weeks double-blind, then 5 weeks open-label Fatigue (MFI-20) and total mood disturbance improved vs placebo, with more energy and emotional well-being; cognition and pain did not change. | 41513981 (opens PubMed)Source [4] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| OEA capsules (including proprietary formulations such as TRPTI) | Varies[1][2][3][4] | No head-to-head human absorption data between OEA products. | Well tolerated in trials up to 15 weeks; no serious adverse events reported.[4][5] | Obesity, PCOS, NAFLD and Gulf War illness trials (125–400 mg/day) |
Studied doses
Doses studied in human trials ranged from 125 mg/day (PCOS) and 250 mg/day (obesity) to 400 mg/day (Gulf War illness), for 8 to 15 weeks. A crossover study gave single doses of 150 and 300 mg.[3][2][4][5]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Diabetes and glucose-lowering medicinesReviewTrials pooled in a meta-analysis found lower fasting glucose and insulin, and a single dose raised GLP-1 and GIP responses, so effects could add to glucose-lowering drugs; not tested together.[1][5]
- Lipid-lowering drugs acting on PPAR-αReviewOEA activates PPAR-α in animal studies, the same target as fibrates; combined use has not been studied.[6][1]
Who should be careful
- People on diabetes medicines
- OEA lowered fasting glucose and insulin in pooled trials; combined use with glucose-lowering drugs has not been studied.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Label dose vs studied doseMost metabolic trials used 125–250 mg/day; the fatigue trial used 400 mg/day. Products sold as appetite aids often list 200 mg per capsule.[2][3][4]
- Branded formsThe incretin study used a proprietary formulation (TRPTI); its single-dose hormone results may not apply to other OEA products.[5]
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
Does OEA help with weight loss?
A 2025 meta-analysis of 10 small trials found modest reductions in weight, waist and fat mass, mostly over 8–12 weeks.[1]
Is OEA the same as PEA?
No. Both are N-acylethanolamines, but OEA is made from oleic acid and studied for appetite and metabolism, while PEA is made from palmitic acid and studied for pain.[6]
Does OEA affect GLP-1?
In one fixed-sequence (non-randomized) crossover study, a single 300 mg dose of a branded OEA raised post-meal GLP-1 and GIP responses in adults with overweight or obesity (BMI 25–34.9); it was not a weight-loss trial.[5]
Can OEA reduce fatigue?
One 52-person trial in Gulf War illness found less fatigue and better mood with 400 mg/day for 10 weeks.[4]
Sources
- [1]Oleoylethanolamide supplementation on cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials.. Front Nutr, 2025. meta-analysis
- [2]The effect of Oleoylethanolamide supplementation on lipid profile, fasting blood sugar and dietary habits in obese people: a randomized double-blind placebo-control trial.. BMC Endocr Disord, 2024. RCT
- [3]Examining the oleoylethanolamide supplement effects on glycemic status, oxidative stress, inflammation, and anti-mullerian hormone in polycystic ovary syndrome.. J Ovarian Res, 2024. RCT
- [4]Oleoylethanolamide supplementation improves mood and reduces fatigue in veterans with GWI in a 15-week randomized, double-blind, placebo-controlled exploratory clinical trial.. Sci Rep, 2026. RCT
- [5]Acute TRPTI™ (oleoylethanolamide) supplementation enhances incretin hormone responses: a fixed-sequence crossover study.. Front Endocrinol (Lausanne), 2026. crossover-RCT
- [6]Oleylethanolamide regulates feeding and body weight through activation of the nuclear receptor PPAR-alpha.. Nature, 2003. animal-study
What changed
- Independent adversarial review: the incretin study (PMID 42528740) is fixed-sequence (not randomized) and enrolled BMI 25–34.9; mechanism and FAQ wording corrected.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Self-review pass (strict second read): obesity trial dose corrected to 125 mg twice daily per abstract; meta-analysis kept out of the evidence table because its abstract gives no pooled participant count. Drug interactions checked explicitly for diabetes drugs and GLP-1 drugs (listed), fibrates (listed, animal mechanism), anticoagulants, blood-pressure drugs, antibiotics, levodopa and chemotherapy (no published signal, not listed).