What the research says about creatine and omega-3 for building muscle after 40, and where the evidence runs thin.
Of the supplements people push on lifters over 40, creatine is the one with the strongest proof for muscle. Omega-3 is a weaker bet.
Start with lifting and protein
No pill replaces training and enough protein. Start with our guide to protein needs after 40.
Creatine: the one with solid evidence
A meta-analysis of 22 studies (721 older adults, average ages 57 to 70) found that people who took creatine while lifting gained about 1.4 kg more lean tissue than those on placebo. They also gained more chest press and leg press strength.
On dose, the International Society of Sports Nutrition says creatine stores can generally be kept up with 3 to 5 g a day. A loading phase (5 g four times a day for 5 to 7 days) fills the stores faster, but you can simply start with the daily dose.
On safety, the same position stand found it safe and well tolerated in healthy people, with no compelling evidence of kidney harm. Weight gain was the only side effect consistently reported. With kidney disease, ask your doctor first.
Key takeaway: Creatine plus resistance training is the best-supported supplement for muscle after 40. 3 to 5 g a day is the standard dose.
Omega-3: promising, but mixed
The case for omega-3 is much thinner. An older meta-analysis of 10 trials (552 older adults) found a small muscle gain of 0.33 kg, with no significant change in handgrip or leg strength. Doses above 2 g a day looked better, at 0.67 kg.
A newer review of 16 studies (2,438 people, average age 69) found that omega-3 did not change lean mass, with or without resistance training. It did find some lower-body strength and timed-up-and-go gains, and the strength gains were larger when people weren’t lifting. It hasn’t been shown to build muscle on top of training.
Key takeaway: Take omega-3 if you want it for other reasons, but don’t count on it for muscle.
What about everything else?
We left out multivitamins, pre-workouts, BCAAs, vitamin D, magnesium and zinc because we didn’t verify claims about them here. For a suspected deficiency, ask a clinician about testing.
Making it a habit
Supplements are easy to forget, and so is regular protein. Proteinly’s automatic eating timer reminds you to eat every 2 hours, which makes spreading your protein through the day a routine. It doesn’t count calories; it just builds the habit.
Frequently asked questions
Do I need to load creatine?
No. The daily 3 to 5 g dose maintains your stores, per the ISSN position stand. Loading just gets you there faster.
Will creatine hurt my kidneys?
In healthy people the ISSN review found no compelling evidence of harm. With existing kidney problems, check with your doctor.
Conclusion
Lift, eat enough protein, and consider creatine at 3 to 5 g a day. Treat omega-3 as optional for muscle. Build the habit, build the body: visit Proteinly, read more at our articles, or follow us on YouTube.