Fish Oil (Omega-3 EPA/DHA)
Fish oil supplies the long-chain omega-3 fatty acids EPA and DHA, taken for triglyceride lowering, cardiovascular and anti-inflammatory support. PED users use it as general cardiovascular support during cycles and specifically to lower triglycerides. Evidence is clear for triglyceride reduction; the cardiovascular-outcome data are mixed and depend heavily on dose and formulation.
01 Overview
EPA and DHA reduce hepatic triglyceride production and have anti-inflammatory and mild antiplatelet effects. High-dose omega-3 reliably lowers triglycerides — the basis for prescription formulations (e.g. icosapent ethyl, omega-3-acid ethyl esters) — while over-the-counter fish oil delivers smaller EPA/DHA amounts per capsule.
Among PED users fish oil is a staple for cardiovascular support during cycles that raise blood pressure, triglycerides or inflammatory markers. Outcome trials are inconsistent: high-dose purified EPA (REDUCE-IT) reduced events, whereas some mixed EPA/DHA trials did not, and very high doses can raise atrial-fibrillation risk. It is generally well tolerated, with fishy reflux and a mild bleeding-tendency increase the main issues.
02 Mechanism
EPA and DHA reduce hepatic VLDL/triglyceride synthesis, incorporate into cell membranes to modulate eicosanoid signalling (anti-inflammatory), and mildly inhibit platelet aggregation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| General cardiovascular support | 1–2 g/day | Oral | Combined EPA+DHA; check label as capsule content varies widely. |
| Triglyceride lowering | 2–4 g/day | Oral | Higher EPA/DHA needed for meaningful triglyceride reduction. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Triglyceride reductionReliably lowers triglycerides in a dose-dependent way. | -15 to -30% at high dose | Clinical | |
| Anti-inflammatory effectMembrane incorporation shifts eicosanoid balance toward less inflammatory mediators. | modest | Observational |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Fishy reflux / GI upsetFishy aftertaste, belching and loose stools, especially at higher doses. | Mild | Common | Observational | |
| Increased bleeding tendencyMild antiplatelet effect; relevant at high doses or with other blood thinners. | Mild | Uncommon | Observational | |
| Atrial fibrillation at very high doseHigh-dose omega-3 has been linked to a small increase in atrial fibrillation risk. | Moderate | Rare | Clinical |