Betaine (Tmg) for Muscle Strength And Growth

Research suggests that betaine supplementation may offer modest benefits for muscle strength, power, and body composition, though the overall evidence remains inconsistent and conclusions should be drawn cautiously. The available literature includes randomized controlled trials, systematic reviews, observational studies, and narrative reviews, with findings that frequently conflict: some trials report meaningful improvements in strength, power output, and favorable hormonal changes such as elevated testosterone, while others — including a 2017 systematic review covering seven RCTs — found no significant ergogenic effect in the majority of studies examined. Studies indicate that betaine may be better supported for certain outcomes, such as upper-body power or CrossFit-style performance, than for others like squat-based lower-body strength or total training volume, and one well-designed RCT found that betaine performed notably worse than creatine as a performance supplement. Limitations across the body of research include small sample sizes, short supplementation durations, the use of multi-ingredient products that make it difficult to isolate betaine's specific contribution, and a general lack of between-group statistical significance even in trials that report within-group improvements, all of which prevent firm conclusions about betaine's effectiveness for muscle strength and growth.