What is Trimethylglycine (Betaine)?

Trimethylglycine (TMG, Betaine) is a naturally occurring compound found in foods like beets and whole grains. In the body it acts as a methyl donor involved in methylation and homocysteine metabolism.

How does TMG help lower homocysteine?

TMG provides methyl groups that help convert homocysteine into methionine. This can reduce elevated homocysteine levels in some people.

What is a typical dosage range for TMG (Betaine)?

Common supplemental amounts are about 1.5–6 g per day. Dosing is often split and may be paired with B vitamins depending on individual needs.

Does TMG improve exercise performance?

Some studies suggest TMG may modestly support power output or reduce fatigue during high-intensity training, but results are mixed. Benefits, if present, tend to be small and vary by person.

Is TMG safe, and who should be cautious?

TMG is generally well tolerated, but higher doses can cause gastrointestinal upset in some people. People who are pregnant or breastfeeding, have medical conditions, or take medications should consult a clinician before using it, especially for liver-related conditions.

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Trimethylglycine
(Betaine)

Moderate study situation·7/10

A higher score indicates better study conditions, but not necessarily effectiveness.

TMG (Betaine) supports methylation and homocysteine reduction, with potential benefits for cardiovascular health and exercise performance.

Cardiovascular Support Exercise Performance Liver Health

dose range

1.5–6 g

Split into two doses with meals

Consumption

Take with main meals for best absorption and GI tolerance.

Not fat-soluble.

Best time

Morning and midday meals are typical. For liver health, doses above 6g/day should be physician-supervised.

Description

Trimethylglycine (TMG, Betaine) is a compound found in beets and whole grains. As a methyl donor, it is involved in key biological processes, including homocysteine metabolism, DNA methylation, and liver function. Betaine is available as a supplement in powder or capsule form, often paired with B vitamins.

benefits

Main effects with level of evidence

Moderate

Note on evidence

There is moderate clinical evidence supporting TMG’s effect on lowering homocysteine, with emerging but less robust evidence for performance and liver health benefits.

Reduces Homocysteine for Cardiovascular Support

Moderate

TMG donates methyl groups to convert homocysteine to methionine, which may lower cardiovascular risk by reducing homocysteine blood levels.

Particularly relevant for: Adults with mild homocysteinemia · Those concerned about heart health

1 · Examine: Betaine 2 · Healthline: TMG Supplement Benefits 7 · EFSA: Betaine for homocysteine

Enhances Exercise Performance

Limited

Supplementation with TMG may increase power output and reduce fatigue, especially during high-intensity resistance training, though results are mixed and effect size is modest.

Particularly relevant for: Athletes · Bodybuilders · Physically active adults

1 · Examine: Betaine 2 · Healthline: TMG Supplement Benefits

Supports Liver Health

Limited

High-dose TMG may reduce liver fat accumulation and support treatment of nonalcoholic fatty liver disease (NAFLD), though use for these conditions requires medical oversight.

Particularly relevant for: Those with NAFLD (under supervision) · Adults with elevated liver fat

3 · WebMD: Betaine Anhydrous 5 · NIH LiverTox: Betaine

Safety & Information

Important safety information & known risks

For educational purposes only • not medical advice

TMG is well-tolerated at normal doses, but high intakes may increase cholesterol and cause digestive issues.

warning notices

High doses (above 6 g/day) can cause diarrhea or GI discomfort.
Possible elevation in LDL cholesterol and triglycerides at high doses; monitor lipid levels if using for extended periods.
Safety in pregnancy and breastfeeding has not been established.

Known interactions with medications

Use caution with medications affecting choline or methylation (e.g., methotrexate); consult a healthcare provider.

Contraindications / special precautions

Individuals with renal (kidney) impairment
Those with elevated cholesterol or heart disease risk without medical supervision
Pregnant or breastfeeding women (insufficient data)

mechanisms of action

Brief explanations of how it works

Methyl Donation in Homocysteine Metabolism

TMG provides a methyl group to homocysteine, converting it to methionine, thereby lowering homocysteine levels in the blood.

1 · Examine: Betaine 7 · EFSA: Betaine for homocysteine

Osmoprotectant and Cell Volume Regulation

Betaine acts as an osmolyte, helping cells maintain volume and fluid balance, which may influence exercise performance.

1 · Examine: Betaine

Influence on Liver Lipid Metabolism

TMG supplementation can reduce hepatic fat accumulation by promoting lipid export from the liver, relevant in NAFLD therapy.

3 · WebMD: Betaine Anhydrous 5 · NIH LiverTox: Betaine

Sources & References

Primary literature and reviews on which these statements are based

7 sources

Examine: Betaine

Healthline: TMG Supplement Benefits

WebMD: Betaine Anhydrous

Examine: Betaine (2021 Review)

Literature review including dosing and safety data.

NIH LiverTox: Betaine

Clinical liver use & safety.

ODS: Betaine Fact Sheet

Official US government information.

EFSA: Betaine for homocysteine

EFSA opinion on betaine and homocysteine.

Laatst bijgewerkt: 21 augustus 2026

This information is for educational purposes only and does not replace medical advice.

Alle voedingsstoffen

Trimethylglycine
(Betaine)

Description

benefits

Reduces Homocysteine for Cardiovascular Support

Enhances Exercise Performance

Supports Liver Health

Safety & Information

mechanisms of action

Methyl Donation in Homocysteine Metabolism

Osmoprotectant and Cell Volume Regulation

Influence on Liver Lipid Metabolism

Sources & References

Vitamins & Vitaminoids

Andere categorieën

Safety & Information

mechanisms of action

Methyl Donation in Homocysteine Metabolism

Osmoprotectant and Cell Volume Regulation

Influence on Liver Lipid Metabolism

Sources & References

Trimethylglycine(Betaine)

Description

benefits

Reduces Homocysteine for Cardiovascular Support

Enhances Exercise Performance

Supports Liver Health

Safety & Information

mechanisms of action

Methyl Donation in Homocysteine Metabolism

Osmoprotectant and Cell Volume Regulation

Influence on Liver Lipid Metabolism

Sources & References

Vitamins & Vitaminoids

Andere categorieën

Safety & Information

mechanisms of action

Methyl Donation in Homocysteine Metabolism

Osmoprotectant and Cell Volume Regulation

Influence on Liver Lipid Metabolism

Sources & References

Trimethylglycine
(Betaine)