TMG (Betaine) Benefits: What Trials Show for Homocysteine, Strength and Cholesterol
TMG, also sold as betaine, reliably lowers homocysteine in trials and may add a little strength. The same higher doses also nudged total cholesterol up, which is the trade-off most product pages leave out.
By Kymata Health Editorial Published Last checked
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NOW Foods TMG, 1000 mg, 100 Tabs
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Label: 3 tablets: 3,000 mg trimethylglycine (betaine anhydrous).
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Key takeaways
From 7 sources- In healthy adults, 1.5, 3 or 6 g of betaine a day lowered fasting homocysteine by 12%, 15% and 20% versus placebo over 6 weeks2.
- A meta-analysis of 17 studies found a small gain in maximal strength, mainly in the lower body3.
- At 4 g a day or more for at least 6 weeks, total cholesterol rose by about 0.34 mmol/L (13 mg/dL) in a meta-analysis of 6 trials4.
- A meta-analysis of 6 trials found lower body fat but no change in body weight or BMI7.
- Prescription betaine is an FDA-approved drug for homocystinuria, a rare inherited disorder6.
What this article covers
2 evidence profilesThe evidence, graded
Pulled from the trial tables in our evidence profiles. Grades follow our evidence-grading policy.
Graded findings
4 rows- BGrade BFasting homocysteine at three dosesImproved Fasting homocysteine was 12%, 15% and 20% lower than placebo at 1.5, 3 and 6 g/day.TMG (trimethylglycine, betaine) · RCT · n=76 · 2003 · PMID 14652361
- CGrade CMaximal strength and jumpingImproved Maximal strength improved (SMD 0.47, 95% CI 0.04 to 0.89), mainly lower body; vertical jump improved only after excluding a low-quality study.TMG (trimethylglycine, betaine) · Meta-analysis · n=317 · 2024 · PMID 39514262
- CGrade CBody fat massImproved Total body fat fell by 2.53 kg and body fat percentage by 2.44 points; body weight and BMI did not change.TMG (trimethylglycine, betaine) · Meta-analysis · n=195 · 2019 · PMID 31623137
- DGrade DMetabolic syndrome risk factors in healthy adultsNo effect Little effect on metabolic risk factors; homocysteine lowering was weak, and plasminogen activator inhibitor 1 rose with betaine.TMG (trimethylglycine, betaine) · RCT · n=63 · 2011 · PMID 20978525
Safety at a glance
From our TMG (trimethylglycine, betaine) evidence profilePublished interactions and cautions only. Each one is cited on our TMG (trimethylglycine, betaine) evidence profile, with its own numbered sources.
Who should be careful
- People watching their cholesterol
- Doses of 4 g/day or more raised total cholesterol in a meta-analysis of 6 trials.
- CBS-deficiency homocystinuria
- In this disorder, prescription betaine can raise methionine to levels linked with brain swelling; it is used only with methionine monitoring.
- Pregnancy and breastfeeding
- No supplement trials in pregnancy were found. The prescription label says limited case reports have not identified drug-associated risks for birth defects or miscarriage, animal reproduction studies have not been done, and there are no data on betaine in breast milk or effects on the breastfed child.
- Liver disease
- LiverTox lists betaine as an unlikely cause of liver injury (score E); in small trials, including people with fatty liver, liver enzyme rises were not reported.
What TMG is
Trimethylglycine (TMG) and betaine, or betaine anhydrous, are the same compound. Betaine HCl is a different product2. Diets supply roughly 0.5 to 2 g a day from foods such as beets, spinach and wheat2.
TMG donates a methyl group that converts homocysteine back into methionine, which is how prescription betaine lowers homocysteine in homocystinuria6.
Homocysteine: the clearest effect
In a 6-week trial of 76 healthy men and women, fasting homocysteine was 12%, 15% and 20% lower than placebo at 1.5, 3 and 6 g of betaine a day2. The effect appeared even at the lowest dose2.
A meta-analysis of 5 trials found that at least 4 g a day for 6 weeks or more lowered homocysteine by about 1.2 µmol/L1. These trials measured homocysteine itself, not heart attacks or strokes12.
The cholesterol trade-off
The doses that lower homocysteine most reliably also raised cholesterol. In a meta-analysis of 6 trials, 4 g a day or more for at least 6 weeks raised total cholesterol by about 0.34 mmol/L, or 13 mg/dL4.
A 6-month trial in 63 healthy young adults at 4 g a day found little effect on metabolic risk factors, weak homocysteine lowering, and a rise in plasminogen activator inhibitor 15. That trade-off matters most for people who are already watching their cholesterol4.
Strength and body composition
A 2024 meta-analysis of 17 placebo-controlled studies in healthy people aged 15 to 60 found that chronic betaine use improved maximal strength, mainly in the lower body3. Vertical jump improved only after a low-quality study was excluded3.
For body composition, a meta-analysis of 6 randomized trials found total body fat fell by 2.53 kg, while body weight and BMI did not change7. Doses and trial lengths varied across these studies7.
Do you need TMG with NMN?
TMG is often sold alongside NAD+ precursors such as NMN. None of the TMG trials cited here gave it together with NMN, and none measured NAD+123.
What the NMN trials did test is covered in the NMN page and in what to check on an NMN label.
Reading a TMG label
Products vary in the amount per serving and in what else they add. These are the points worth checking:
- Grams of betaine (TMG) per day at the label serving. Trials used 1.5 to 6 g a day23.
- Whether the daily amount reaches 4 g, the level at which total cholesterol rose in the meta-analysis4.
- Whether the product is betaine anhydrous (TMG) or betaine HCl, which is a different product2.
- Other added nutrients such as folate or vitamin B12, which also act on homocysteine; see the folate and vitamin B12 pages.
Before you try it
No safety data for supplemental doses in pregnancy were found in the trials cited here2. In the inherited disorder CBS-deficiency homocystinuria, prescription betaine can raise methionine to levels linked with brain swelling, and it is used only with methionine monitoring6.
The full evidence table is on the TMG page.
Quick answers
Common questions
4 answersIs TMG the same as betaine?
Yes. Trimethylglycine and betaine anhydrous are the same compound; betaine HCl is a different product2.
How much TMG was studied?
Does TMG raise cholesterol?
A meta-analysis found 4 g a day or more raised total cholesterol by about 0.34 mmol/L4.
Does TMG help you lose weight?
A meta-analysis of 6 trials found lower body fat but no change in body weight or BMI7.
Keep reading
Full evidence profiles
Every graded study, studied doses, interactions and safety- Amino acidTMG (trimethylglycine, betaine)TMG (trimethylglycine, or betaine) is a methyl donor found in beets, spinach and wheat; it helps recycle homocysteine into methionine.BGrade B
- NAD+ / longevityNMN (nicotinamide mononucleotide)NMN is a precursor of the coenzyme NAD+; in rodents, aging and obesity impair NAD+ synthesis.CGrade C
Related articles
4 articles- ArticleBest NMN Supplement? What the Label Can and Can't Tell YouWhat is the best NMN supplement, and what should I look for on the label?
- ArticleDoes NMN Work? It Raises NAD, but Pooled Trials Find Little Else So FarDoes NMN really work?
- ArticleIs NMN Legal in the US? FDA Reversed Its 2022 Position on September 29, 2025Is NMN legal to sell as a supplement in the US?
- ArticleNAD+ Blood Tests: What the Number Shows, What It Can’t, and Why There Is No Agreed Normal RangeWhat does an NAD+ blood test actually show?
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Where to buy TMG (trimethylglycine, betaine)
Products from brands we partner with that contain TMG (trimethylglycine, betaine). Check the amount per serving against the doses studied, and the label for other ingredients.
TMG (trimethylglycine, betaine) products from partner brands
3 products Paid links · we earn a commission- Quick pickHerbsProNOW Foods TMG, 1000 mg, 100 Tabs
3 tablets: 3,000 mg trimethylglycine (betaine anhydrous)
$15.62one-timeChecked Oct 14, 2026 - SupersmartTMG (Trimethylglycine)5% off with the Supersmart newsletterGet 5% off with the newsletter (paid link, opens in new tab)
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3 tablets: 2,250 mg betaine anhydrous (750 mg per tablet); 33 servings
$22.00one-time$18.70subscribeChecked Oct 11, 2026 - Renue by ScienceRenue by Science TMG Methylation Essentials (120 capsules)Subscribe & Save 10%
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Choose the Subscribe & Save option on the product page.
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- Offer terms from Renue by Science’s site, checked Oct 15, 2026. Offers can change; the brand's checkout is final.
Serving size 2 capsules; the product page lists 900 mg TMG (betaine). Check the label for any other added nutrients
$27.95one-time$25.16subscribeChecked Oct 15, 2026
References
7 sources. Numbers in the text link here.
Sources cited in this article
7 sources- 1Betaine supplementation decreases plasma homocysteine in healthy adult participants: a meta-analysis.J Chiropr Med, 2013 · PMID 23997720
- 2Low dose betaine supplementation leads to immediate and long term lowering of plasma homocysteine in healthy men and women.J Nutr, 2003 · PMID 14652361
- 3Effects of chronic betaine supplementation on exercise performance: Systematic review and meta-analysis.J Sports Sci, 2024 · PMID 39514262
- 4Betaine Supplementation Moderately Increases Total Cholesterol Levels: A Systematic Review and Meta-Analysis.J Diet Suppl, 2021 · PMID 31809615
- 5Long-term effect of betaine on risk factors associated with the metabolic syndrome in healthy subjects.Eur J Clin Nutr, 2011 · PMID 20978525
- 6CYSTADANE (betaine anhydrous for oral solution) prescribing informationDailyMed, U.S. National Library of Medicine, 2026
- 7Effect of Betaine on Reducing Body Fat-A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Nutrients, 2019 · PMID 31623137
TMG (trimethylglycine, betaine) and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. Product links on this page are paid partner links.