Does betaine help you get stronger?

Short answer

A little. Taking it for 7 days or more raised leg strength and jumping slightly more than a placebo. But upper-body strength and muscle mass didn't change, and over the same period creatine raised power while betaine didn't.

Does betaine help you get stronger?
'Betaine → more strength → more muscle' — does this formula hold?
Betaine is found in foods like beets and is a common pre-workout ingredient. Ads say it makes you stronger and helps you build muscle. We split strength and muscle mass and checked each against the research.
Pooled together, strength went up
7+ days of use raised max strength, especially in the legs
A 2024 analysis that pooled 17 studies with 317 people found that taking betaine for at least 7 days raised max strength more than a placebo. The difference was clear for lower-body strength. Jump height also rose more.
But not every kind of strength
Upper-body strength and endurance didn't change
In the same analysis, upper-body max strength, cycling sprint power and muscular endurance showed no difference. A 2026 analysis of 119 studies found the betaine group's countermovement jump was 3.72 cm higher than placebo. The effect was concentrated in the legs and jumping.
But study by study
It rarely showed up in your heaviest lift
A review of 7 trials found only 2 showed gains in strength or power. In one study 23 people took 2.5 g a day for 6 weeks, and in another 23 people took it for 8 weeks; neither showed a difference from placebo in max bench press or squat. The effect was small, so studies of about 10 people per group couldn't pick it up.
So did muscle grow?
No difference in muscle or body fat
A 2022 analysis of betaine studies found lean mass (muscle and everything except fat) rose 0.61 kg more, but the difference wasn't meaningful. Body weight, fat mass and body fat percentage didn't differ either. Splitting by age, sex, use of 8 weeks or more, or 4 g a day or more gave the same result.
Compared with creatine
Creatine raised power; betaine didn't
People who didn't train took betaine (2 g a day), creatine (20 g a day), both, or a placebo for 10 days. The creatine groups gained more stored muscle energy and more squat and bench press power, but betaine alone was no different from placebo. Adding betaine to creatine gave nothing extra.
Does a bigger dose work better?
5 g and 5 g a day were no different
In a trial where 43 CrossFit athletes took betaine and a placebo for 3 weeks each, their CrossFit workout score rose 8.7% during the betaine period. There was no difference between 2.5 g and 5 g a day, and 30-second all-out cycling power and body composition didn't change.
Bottom line: a little strength, no extra muscle
The effect showed up, small, in leg strength and jumping
Taking betaine for 7 days or more raised leg strength and jumping a little. Upper-body strength and muscle mass didn't change, and the effect wasn't big enough to show up as a heavier max lift within a single study. Studies used about 2.5 g a day, and if strength is the goal, creatine gave clearer results.