If you go around your local gym telling people they can increase muscle mass gains by consuming fish oil, they will probably present you with a weird look. Nonetheless, there might actually be some truth to that seemingly crazy, random claim.
Because when combining the outcome of a very recent study with several older ones, a theoretical case for the otherwise unknown muscle building effects of fish oil intake can be made. This is quite surprising to me, as this is not a beneficial attribute to daily fish oil intake I have come across before.
Now, being a nerd I have of course come across all the regular researched benefits of fish oil, including but definitely not limited to lowering triglycerides, combating depression, reducing blood pressure, and the list goes on. All in all, there is substantial evidence proving a myriad of health benefits of sufficient fish oil intake.
But muscle growth? Actual stand-alone muscle growth signaling caused by fish oil? Sounds fishy. Hohoho. But let’s delve into the recent talk on this.
Can Fish Oil build muscle?

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This is a question which has now gained traction, as a recent 2018 study conducted over the course of 8 weeks set out to research the effects of Fish Oil intake on mTOR stimulation. To give the worlds fastest crash-course in mTOR, it is an enzyme which when activated, regulates among other things protein synthesis – the process for the creation of new muscle mass.
The study grouped 18 subjects into two groups and made both groups follow an 8-week resistance training program. One group consumed 1 gram of EPA/DHA per day while the other group consumed a placebo supplement.
After 8-weeks, measurements of lean body mass were conducted, and when taking an initial look at the results, they are pretty immense. So immense so that the EPA/DHA omega-3 group saw a bit more than 4 times as much growth in lean body mass compared to the placebo group.
The authors’ results note states:
“Krill oil significantly stimulated mTOR signaling in comparison to S-PC and control. No differences for markers on the CMP, CBC, or UA were observed. Krill oil significantly increased lean body mass from baseline (p=0.021, 1.4 kg, +2.1%); however, there were no statistically significant differences between groups for any measures taken.”
Study limitations
And as you can see from the authors’ notes – here’s the first of several limitations to this study. Statistical significance couldn’t be established based on the results, which makes sense considering the small size of the study: just 9 subjects in each group.
A further limitation could be argued in the case of overall nutrition, as the study gives no mention of dietary control of the subjects. Thus, food intake was uncontrolled, which when coupled with the low number of subjects raises the possibility of chance.
Last but not least, a US-based company which is in the fish oil business did a portion of the funding of the execution of the study. Now, you may think this immediately disqualifies the results, but company-funding is somewhat widespread, and while it’s something we should be wary off – it doesn’t instantly mean these researches fiddled with the results. Such meddling could have grave results for their work.
Do other studies support muscle building traits of fish oil?

Looks like me browsing research papers. I mean except I’m male. Don’t wear glasses. Don’t have (but would kill to have) long lush brunette hair…
So, on its own, this new 2018 study is interesting but overall underwhelming. However, what does other research within this specific area suggest?
If we go back to 2017, this study was constructed in much the same way as the 2018 study, with two groups getting either fish oil (here at 1.4 g per day) or a placebo. Results? Fish oil group “improved body composition” and “maximal strength of knee extension” (They only did leg extensions) when compared to the placebo group.
Improved body composition, in this case, means both a decrease in body fat mass and an increase in lean body mass. Not too bad! Once again we’re met with some limitations though, biggest one being the low sample size of just 15 subjects.
Nonetheless, we turn our sights towards two 2011 studies (one and two) which despite some overall differences in setup and execution, also showed promising results, indicating a muscle protein anabolic response following omega-3 supplementation. Limitations? Yeah, you guessed it. Low sample sizes. Oh well.
So does Fish oil = Muscle Growth? + My recommendation
What do we make of all this? Well, I say “all this”, but in reality, and in the greater scheme of nutritional literature, the amount of studies on this topic isn’t sufficient to conclude much.
With that being said, these 4 studies, however limited, did produce quite interesting results, so much so that I am personally inclined to think that Fish Oil supplementation does interact with mTOR/anabolic signaling in some way, additive to the effects of working out. How big this effect is, is hard to tell. Ultimately, more research is needed, and I will do my part to look out for it.
As for Fish Oil supplementation, I will repeat myself from other posts: unless you get good fatty fish several times a week, you should supplement with Fish Oil. This recommendation is not based on anything related to potential anabolism/muscle growth – it’s simply based on a host of other, well-established health benefits of regular Fish Oil consumption.
I recommend at least 1-1.5 grams worth of EPA/DHA Fish Oil per day, and myself hover around the 1.5-2 grams per day mark, year round.
If you are on the lookout for a good value for money Fish Oil supplement, I recommend Dr. Tobias Triple Strength Burpless Non-GMO NSF-Certified Fish Oil. You can check out prices and offers here.
It contains a high amount of EPA/DHA per serving compared to many other brands and is incredibly well-reviewed with more than 4.6 stars out of 5 based on over 11000 customer reviews. The price seems to be in the mid to high end for Fish Oil supplements, but that likely correlates to the high EPA/DHA content per serving, which also means you have to swallow less of them to reach your target intake.
Thank you for reading, and feel free to share!
Alex,