Head to head
Omega-3 against Niacin
Two lipid-modifying supplements with the same instructive history: both reliably move the markers they target and both failed to prevent events in large randomised trials. Niacin's failures were HPS2-THRIVE and AIM-HIGH; omega-3's two large trials reached opposite conclusions and the difference may be the placebo.
Column A
Omega-3Long-chain omega-3 fatty acids (EPA and DHA)
Two large outcome trials reached opposite conclusions and the difference may be the placebo. Blood levels track strongly with living longer, supplements mostly do not, and the atrial fibrillation risk is real and dose-dependent.
Column B
NiacinNicotinic acid, niacin, the acid form of vitamin B3
The only compound in the NAD pathway ever tested against hard cardiovascular outcomes, in 25,673 patients in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every lipid it was supposed to move and prevented no events in either trial, and HPS2-THRIVE found excess serious adverse events including infection and bleeding.
Side by side, on the facts we can check
| Attribute | Omega-3 | Niacin |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Icosapent ethyl and omega-3-acid ethyl esters are FDA-approved prescription drugs for severe hypertriglyceridaemia, with icosapent ethyl carrying a cardiovascular risk reduction indication. Over-the-counter fish oil is a dietary supplement and is not approved to treat anything. | Extended-release nicotinic acid is an FDA-approved prescription lipid drug in the United States, though its clinical use collapsed after AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The extended-release niacin with laropiprant combination used in HPS2-THRIVE was withdrawn worldwide after the trial reported. |
| Half-life | Roughly 2 to 3 days for plasma phospholipid EPA and DHA. Red cell membrane incorporation, which is what an omega-3 index measures, is far slower and takes about 120 days to reach steady state and about the same to wash out, so retest the index at four months rather than at one. | Under an hour for immediate-release nicotinic acid. Extended-release formulations were built specifically to stretch that out and blunt the flush, and the dose is not interchangeable between forms. |
| Molecular weight | 302.5 Da for EPA and 328.5 Da for DHA as free acids. Supplement forms are ethyl esters or triglycerides, which differ in absorption. | 123.1 Da |
| Mechanism | EPA and DHA incorporate into cell membrane phospholipids, displacing arachidonic acid and altering membrane fluidity and the substrate pool for eicosanoid synthesis. They are precursors to resolvins and protectins, which actively terminate inflammation rather than merely failing to promote it. EPA lowers hepatic triglyceride synthesis and secretion, which is the basis of the prescription high-dose indication. DHA is a major structural lipid in retina and brain. The membrane effects also alter cardiac ion channel behaviour, which is the most plausible route to the atrial fibrillation finding. | Nicotinic acid enters NAD synthesis through the Preiss-Handler pathway rather than the NAMPT salvage route, which is why it is a genuinely potent NAD booster and why a 2026 human study proposed that gut bacterial conversion of NR and NMN into nicotinic acid may be how those two expensive precursors work at all. Its lipid effects are separate and act mainly through inhibition of adipocyte lipolysis and hepatic diacylglycerol acyltransferase, reducing free fatty acid flux to the liver and VLDL output. The flush is a third, distinct mechanism: nicotinic acid activates the receptor GPR109A on immune cells in skin, releasing prostaglandins D2 and E2 that dilate cutaneous vessels. Mouse knockout work established each link in that chain. The laropiprant in HPS2-THRIVE was a prostaglandin D2 receptor antagonist added to block exactly this, which worked for the flush and did nothing for the outcomes. |
| Human studies cited | 5 | 5 |
| Legal status, US | Sold as a supplement | FDA-approved prescription lipid drug, also sold over the counter as a supplement |
Frequently asked questions
What is the difference between Omega-3 and Niacin?
Omega-3: Two large outcome trials reached opposite conclusions and the difference may be the placebo. Blood levels track strongly with living longer, supplements mostly do not, and the atrial fibrillation risk is real and dose-dependent. Niacin: The only compound in the NAD pathway ever tested against hard cardiovascular outcomes, in 25,673 patients in HPS2-THRIVE and 3,414 in AIM-HIGH. It moved every lipid it was supposed to move and prevented no events in either trial, and HPS2-THRIVE found excess serious adverse events including infection and bleeding.
Which has stronger research evidence, Omega-3 or Niacin?
This database does not grade compounds. It counts what was run in people: 5 of the 5 studies cited on the Omega-3 profile were human work, against 5 of 6 for Niacin. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Omega-3 and Niacin FDA-approved?
Omega-3: Icosapent ethyl and omega-3-acid ethyl esters are FDA-approved prescription drugs for severe hypertriglyceridaemia, with icosapent ethyl carrying a cardiovascular risk reduction indication. Over-the-counter fish oil is a dietary supplement and is not approved to treat anything.. Niacin: Extended-release nicotinic acid is an FDA-approved prescription lipid drug in the United States, though its clinical use collapsed after AIM-HIGH and HPS2-THRIVE. Lower-dose nicotinic acid is also sold over the counter as a supplement. The extended-release niacin with laropiprant combination used in HPS2-THRIVE was withdrawn worldwide after the trial reported..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.