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7 peer-reviewed studies
What the evidence says
Most TMG studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from high-quality meta-analyses and randomised trials published 2017–2025 with a typical study size of 21 participants.
Based on 7 studies · 4 meta-analyses · 1 RCT · 21 total participants
Confidence
HighBy outcome
6 studies in the last 5 years · Latest meta-analysis: 2024
A meta-analysis examined chronic betaine supplementation on exercise performance.
Zawieja E et al. · Journal of sports sciences (2024)
A meta-analysis found betaine supplementation moderately RAISES total and LDL cholesterol.
Zawieja EE et al. · Journal of dietary supplements (2021)
A systematic review found betaine supplementation may improve muscle strength and power.
Ismaeel A et al. · Journal of strength and conditioning research (2017)
A meta-analysis found betaine supplementation does NOT meaningfully improve body composition.
Ashtary-Larky D et al. · The British journal of nutrition (2022)
A meta-analysis assessed betaine's effects on cardiovascular markers.
Ashtary-Larky D et al. · Critical reviews in food science and nutrition (2022)
A randomized trial found betaine improved 60-km cycling time-trial performance.
Nieman DC et al. · Nutrients (2025)
A narrative review summarized betaine's roles in aging, methylation, and metabolism.
Zawieja E et al. · Ageing research reviews (2025)