betaine

Quick Answer Betaine, also called trimethylglycine (TMG), is a methyl donor that lowers homocysteine, supports liver health, and may improve mood, body composition, and exercise performance. New 2025–2026 clinical research found that lower daily doses (1–8 grams) meaningfully reduce liver enzymes in MASLD (the condition formerly called NAFLD) with far fewer GI side effects than