Betaine

A small molecule made of glycine carrying three methyl groups, first isolated from sugar beet, and present in ordinary food — wheat bran, wheat germ, beetroot, spinach and quinoa are the richest sources.

Betaine does two separable jobs. As an osmolyte it accumulates inside cells and helps them keep their volume under stress, which is the loose mechanistic argument for a training effect. As a methyl donor it hands one of its three methyl groups to homocysteine via betaine-homocysteine methyltransferase, regenerating methionine and therefore S-adenosylmethionine, the body's general-purpose methyl currency. The second job is genuinely well characterised — the pharmaceutical form is licensed at 6 g a day for inherited homocystinuria. The step from that chemistry to a heavier squat remains an inference rather than a demonstrated chain.

Acts as an osmolyte that helps cells hold their volume, and donates methyl groups in normal one-carbon metabolism. It has been studied for maximal strength in resistance-trained people.

Resistance-trained people willing to take 2.5 g a day for six weeks or more and judge it on a lower-body strength number rather than a feeling — and willing to weigh that dose against EFSA's 400 mg safe-addition level first. Not for anyone with a methionine metabolism disorder. Worth a conversation with a doctor if you are actively managing cholesterol, because gram doses moved lipids in controlled trials.

Daily and consistently, on training and rest days alike — it is a loading ingredient, not an acute one, and nothing in the literature supports pre-workout timing. Food makes no meaningful difference to absorption. It is often paired with choline, folate and B12, which share the same methyl economy. In IGNITE there is nothing to time.

Nothing you can feel, at any dose. Betaine produces no buzz, no pump and no tingle. At 2.5 g daily for six weeks the honest expectation is a small improvement in a lower-body maximal strength test that you would only detect by measuring it. At roughly 78 mg, expect nothing at all.

Cholewa et al. (2013, JISSN) gave 23 resistance-trained men 2.5 g a day for six weeks alongside a periodised programme and reported improved body composition, arm size and bench-press work capacity, a tendency toward improved power (p = 0.07), and no improvement in strength. Zawieja et al. (2024, Journal of Sports Sciences 42:2131–2144) pooled 17 studies and 317 participants and found a significant effect on maximal strength (SMD 0.47, 95% CI 0.04–0.89), concentrated in the lower body (SMD 0.49), plus vertical jump (SMD 0.36) after excluding one low-quality study — and no significant effect on upper-body strength, cycling sprint power, bench-press throw power or muscular endurance. Ismaeel (2017, Journal of Strength and Conditioning Research 31:2338–2346) found 7 trials, all rated excellent quality, of which only 2 reported any increase in strength or power. On safety, Olthof et al. (2005, PLoS Medicine) pooled four randomised trials in 151 healthy adults: 6 g a day for six weeks raised LDL by 0.36 mmol/L (11%) and triglycerides by 0.14 mmol/L (13%), with the same direction but no statistical significance at 1.5 g and 3 g. A later meta-analysis of six trials at 4 g a day or more (Journal of Dietary Supplements, 2021) found total cholesterol up 0.34 mmol/L with no significant change in LDL, HDL or triglycerides. EFSA's novel food opinions (2017, 2019) set 6 mg/kg bodyweight a day — about 400 mg for an adult — as the safe addition to background diet, and noted that some supplements already on the EU market exceed it. Betaine anhydrous (Cystadane) is a licensed medicine dosed at 6 g a day for inherited homocystinuria, which is not a supplement use. Body-composition findings are reported here as literature and are not the basis of any claim; no fat-loss claim is made or implied. What is not supported: any performance effect at sub-gram doses.