TMG (Betaine) Lowers Homocysteine 32%, Liver Fat 18% in 12-Week RCT
TMG (trimethylglycine, betaine) 3g/day for 12 weeks improved homocysteine and NAFLD markers in 110 patients, according to 2025 data in Hepatology. A natural methyl donor that backs up the methionine cycle for SAM-e regeneration.
The trial enrolled 110 patients with NAFLD plus elevated homocysteine (>15μmol/L) across 12 weeks. Results: homocysteine -32% (mean 18.7 → 12.7μmol/L), ALT -22%, AST -18%, liver fat content (MRI-PDFF) -18%, NAFLD score -27%, HOMA-IR insulin resistance -15%. Adverse events: mild GI discomfort (8%), some fishy body odor.
What is TMG
TMG (trimethylglycine, also called betaine) is glycine with three methyl groups attached. Dietary sources: beetroot, spinach, quinoa, whole wheat, shrimp. The body donates a methyl group from TMG to homocysteine → methionine regeneration → SAM-e (S-adenosyl-methionine, the universal methyl donor).
Available forms:
- TMG powder: 1~6g/day divided (most cost-effective)
- TMG capsules 500mg, 1g
- Beet extract (nitrate + TMG matrix)
- Standalone or matrix with B-complex (B6, B12, methylfolate)
Multi-target mechanisms
1. Methionine cycle — homocysteine → methionine regeneration:
- Cycle: methionine → SAM-e → SAH → homocysteine → methionine (regenerated)
- Two paths from homocysteine → methionine:
- Folate·B12 path: MTR (methionine synthase), uses methylfolate methyl
- Betaine (TMG) path: BHMT (betaine-homocysteine methyltransferase), uses TMG methyl
- BHMT path serves as backup when B12·folate are deficient
- Elevated homocysteine → cardiovascular, cognitive, osteoporosis risk markers
2. SAM-e regeneration — universal methyl donor:
- SAM-e methylates DNA, RNA, proteins, neurotransmitters, phospholipids
- Methylation governs gene expression, aging clocks, mood, neuroprotection
- TMG fuels SAM-e regeneration
3. Liver fat metabolism — NAFLD target:
- Methionine deficiency → low PEMT enzyme → low phosphatidylcholine → low VLDL secretion → liver fat accumulation
- TMG preserves methionine·choline → PEMT activity restored → liver fat exported
- NAFLD/MASH (current term) adjunct
4. Exercise performance:
- Some trials: TMG 2.5g/day 6 weeks anaerobic performance +5~7% (repeat sprints, power)
- Mechanism: cellular hydration, osmotic stability, contraction efficiency
- ISSN position statement lists TMG as performance-supportive
5. Topical hydration:
- Betaine is a natural moisturizing factor (NMF)
- Standard cosmetic humectant
Clinical data
- Hepatology 2025 RCT 110 patients 12 weeks: homocysteine -32%, liver fat -18%
- 2024 trial: MTHFR variant women 12 weeks TMG 3g/day, homocysteine -45%
- 2023 trial: athletes 6 weeks TMG 2.5g/day, repeat sprints +6%
- 2022 trial: NAFLD 12 weeks TMG + choline + methionine matrix, ALT -32%
Cautions
- MTHFR C677T variant: TMG effect amplified (folate path bypass). Physician assessment recommended
- Kidney disease: monitor homocysteine, physician assessment
- High dose (>6g/day): fishy body odor, some GI discomfort
- Pregnancy·lactation: limited data, physician assessment (homocysteine monitoring may be valuable)
- Methylation sensitivity: some experience anxiety, palpitations from strong methyl donation. Magnesium·niacin support or dose reduction
- Divided dosing: 3g/day = 1g × 3 with meals
- Adequate hydration: osmotically active molecule
- Reassess at 3 months: re-test homocysteine, liver enzymes
Synergy matrix
- TMG + Methylfolate + Methyl-B12 + B6: methylation matrix (homocysteine target)
- TMG + Choline + Inositol: NAFLD matrix
- TMG + Creatine: performance matrix
- TMG + DIM + CDG: hormone + methylation integration
Consumer message
For homocysteine, liver fat, and methylation, dietary methionine alone falls short. TMG, derived from beets and spinach, delivers cumulative 12-week reductions: homocysteine -32%, liver fat -18%, NAFLD score improvement — a backup pathway for the methionine cycle, clinically validated. Caveats: MTHFR variant assessment, kidney monitoring, fishy odor at high dose, pregnancy and methylation sensitivity care, divided dosing with hydration, dietary insufficiency. Pairs with B-complex, choline, creatine. A multi-target molecule in tetrapod’s spring 2026 methylation and detox matrix.