Supplement · Performance & ergogenic aids
Betaine (TMG)
Also known as: Trimethylglycine, TMG
Trimethylglycine, with early evidence for power output and a role in methylation.
- Evidence
- Silver· human data
- Sources cited
- 1
- Last reviewed
- 22 July 2026
Betaine, or trimethylglycine, is found in beetroot and grains and acts as an osmolyte and a methyl donor (helping recycle homocysteine). Both roles have been proposed to benefit training.
A handful of trials suggest small improvements in power output and body composition with a few grams daily, but results are inconsistent and the effect, if real, is modest. It is a reasonable low-risk 'might help a little' ingredient rather than a proven performance booster.