Benefits
Supplies EPA and DHA from whole salmon
Salmon oil is a whole-fish oil that provides the marine omega-3 fatty acids EPA and DHA in their natural triglyceride form. In trials, taking it raises the share of these omega-3s carried in blood and red blood cells. The wider health research on what EPA and DHA do is covered on the Fish Oil and Omega-3 Fatty Acids pages.
Triglyceride support at fish-oil doses
Marine omega-3s lower blood triglycerides at higher intakes, an effect best documented for concentrated EPA and DHA. In an open-label study, 3 g a day of salmon oil lowered triglycerides in adults whose levels had been raised by HIV medicines. Salmon oil can add to this, but only if it supplies enough EPA plus DHA, which a whole-fish oil carries less of per gram.
EPA and DHA per gram are lower than in concentrated fish oil
Because salmon oil is a whole oil and not a purified concentrate, each gram carries less EPA and DHA than concentrated or prescription fish oil. In a crossover trial, a triglyceride salmon oil raised whole-blood EPA by roughly a quarter of the rise seen with a concentrated fish oil, each taken at its own label dose. Read the EPA plus DHA figure on the label, not the total oil.
Raises blood omega-3 status much like eating salmon
In a trial that compared salmon oil capsules with eating salmon, red blood cell omega-3 levels rose by a similar amount once the EPA plus DHA dose was matched. Eating the fish itself also raised blood selenium, which the capsules did not. For the single job of raising omega-3 status, matched doses of oil and whole fish behaved alike.
Carries astaxanthin and vitamin D that vary by source
Whole salmon oil carries the carotenoid astaxanthin, which gives salmon its color, and small amounts of vitamin D. Food-composition studies find wild salmon holds several times more astaxanthin and more vitamin D than farmed salmon, and levels vary widely, so the amount in any given oil depends on the fish and how it was processed.
Mechanism of action
Omega-3s are built into cell membranes
EPA and DHA from the oil are incorporated into cell membrane phospholipids, and the share they reach in red blood cells is measured as the omega-3 index. Once in membranes they also serve as raw material for signaling molecules that the body makes during inflammation.
The whole-fish structure affects absorption
In a postprandial human crossover study, the natural structure of salmon changed how its omega-3 fats were digested and absorbed: intact salmon gave higher plasma EPA and DHA than minced salmon or defatted salmon plus oil, partly because fat left the stomach at different rates. The food matrix, not just the dose, shapes bioavailability.
Triglyceride form and the astaxanthin it carries
The EPA and DHA in salmon oil sit in triglyceride form, the same form found in fish and the form the body packages dietary fat in. Astaxanthin, the carotenoid that colors salmon, is an antioxidant that in laboratory work helps protect such oils from oxidation; this is background chemistry rather than a proven health effect in people.
Clinical trials
Open-label, randomized crossover comparing concentrated triglyceride fish oil, ethyl-ester fish oil, krill oil and triglyceride salmon oil, each at its label dose for 28 days, run by a contract analytical lab. (Laidlaw et al. 2014, Lipids Health Dis)
35 healthy adults, each taking all four products in random order with 4-week washouts.
Whole-blood omega-3 rose most with concentrated triglyceride fish oil, then ethyl-ester fish oil, then triglyceride salmon oil, then krill oil. The salmon oil serving supplied 180 mg EPA and 220 mg DHA, and its whole-blood EPA rise was about a quarter of that from the concentrated fish oil; markers of cardiovascular risk improved more with the concentrated product. For the general population the authors said form and dose may not matter, but for lowering cardiovascular risk they may.
Randomized, open-label, multicenter study (parallel plus crossover) of salmon oil 1 g three times a day for 24 weeks, with triglyceride change as the main outcome. (Baril et al. 2007, HIV Clin Trials)
58 adults with HIV and dyslipidemia linked to antiretroviral therapy; many also used statins or fibrates.
After 12 weeks, triglycerides fell by about 1.1 mmol/L on salmon oil versus a small rise in the no-treatment group, and fell further when the control group later crossed over to salmon oil. The effect held after accounting for other lipid-lowering drugs, and the oil was generally well tolerated. This was an open-label study in a patient group, not a placebo-controlled trial in healthy people.
Randomized 8-week study assigning adults to eat salmon twice a week or take 2, 4 or 6 salmon oil capsules a day, with red blood cell omega-3 and selenium status measured. (Stonehouse et al. 2011, Br J Nutr)
44 healthy volunteers in New Zealand, a population with marginal omega-3 and selenium status.
At a matched intake of about 0.82 g a day of long-chain omega-3, red blood cell omega-3 rose by a similar amount whether it came from salmon or from capsules. Eating salmon also raised blood selenium while the capsules did not, because the fish supplied far more selenium than the oil. Omega-3 status improved alike, with whole fish adding a selenium benefit.
Postprandial randomized crossover comparing meals of intact salmon, minced salmon and defatted salmon plus oil with identical nutrients, with 6 hours of blood sampling plus a parallel lab digestion model. (Ahmed Nasef et al. 2021, Food Funct)
13 healthy women.
Plasma EPA and DHA were significantly higher after eating intact salmon than after the other two meals, and the lab model showed the defatted salmon plus oil meal emptied fat from the stomach faster. The authors concluded that the natural structure of the fish, not only the amount of omega-3, affects how much EPA and DHA is absorbed. A small, short postprandial study of absorption, not of health outcomes.
Randomized, double-blind, controlled crossover of a krill-and-salmon oil blend versus canola oil, 5 g a day for 8 weeks each, with insulin sensitivity from an oral glucose tolerance test as the main outcome. (Albert et al. 2015, Am J Clin Nutr)
47 overweight but otherwise healthy men, mean age about 47.
Unexpectedly, insulin sensitivity was about 14% lower on the krill-and-salmon blend than on the control oil, and lower still after adjusting for the blood omega-3 rise. The authors concluded the blend was associated with reduced insulin sensitivity in overweight men. The product was a blend rather than salmon oil alone, but the result is a reason not to assume a marine-oil blend only helps metabolic markers.