Betaine Anhydrous

non-nutrient/non-botanicalanthocyanidin betaine

Best before bed

What is it

Betaine anhydrous is the water-free form of betaine (trimethylglycine, or TMG), a naturally occurring compound found in foods such as beets, spinach, and wheat bran. It is the most common supplemental form, used for methylation support, homocysteine reduction, and athletic performance.

How it works

Betaine anhydrous donates methyl groups in one-carbon metabolism, particularly converting homocysteine back to methionine via the enzyme BHMT. This pathway is especially important when folate intake is suboptimal. Methionine produced is then used to form S-adenosylmethionine (SAM), the body's universal methyl donor for hundreds of biological methylation reactions affecting DNA, neurotransmitters, hormones, and lipid metabolism. In cells, betaine functions as an osmolyte, helping cells maintain volume and structural integrity under osmotic stress. This is particularly important in the kidney medulla and may underlie betaine's effects on hydration and cell function during physical stress. For athletic performance, betaine anhydrous has been studied for its effects on power output, endurance, and body composition. The mechanisms likely involve a combination of cellular osmolyte effects, methyl donor support for creatine synthesis, and possibly modulation of cellular signaling pathways involved in muscle adaptation.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Homocysteine reduction

Grade A

Strong evidence

Strong evidence supports betaine anhydrous for reducing elevated blood homocysteine. FDA-approved for genetic homocystinuria.

Exercise performance (power, endurance)

Grade B

Good evidence

Multiple clinical trials suggest 2,500 mg per day for 1 to 2 weeks improves measures of muscular power, endurance, and certain strength performance. Effects are modest but reasonably reproducible.

Body composition

Grade C

Moderate evidence

Some research suggests betaine may modestly support fat loss and muscle gain when combined with resistance training, possibly through metabolic and hormonal effects.

Liver health (NAFLD)

Grade C

Moderate evidence

Some studies suggest betaine anhydrous may improve markers of non-alcoholic fatty liver disease. Evidence is moderate.

Cardiovascular outcomes

Grade D

Mixed evidence

Although betaine lowers homocysteine, large trials of homocysteine-lowering have not consistently reduced cardiovascular events. Specific cardiovascular effects of betaine are unclear.

3 commercial forms

Betaine anhydrous (TMG) powder

Pure form; mixes easily in water.

Cost-effective; common in pre-workout formulas. Mildly salty taste.

Betaine anhydrous capsules

Convenient pre-measured doses.

Easier to take than powder; may require multiple capsules per dose.

Pre-workout blends with betaine

Combined with creatine, beta-alanine, caffeine, and other performance ingredients.

Common in commercial pre-workout products at standard 2,500 mg dose.

Dosage

Most studies of exercise performance use 2,500 mg per day, typically as a single dose. For homocysteine reduction, 1,500 to 6,000 mg per day is common. Prescription betaine anhydrous for homocystinuria uses much higher doses (6 to 20 g per day). There is no established Tolerable Upper Intake Level.

When and how to take it

WHEN: Take 30 to 60 minutes before workouts for performance effects. Can otherwise be taken at any consistent time. With meals reduces GI upset. HOW: Take with food and water. Powder dissolves easily in water; the taste is mildly salty. Split larger daily doses into 2 administrations.

Food sources

Food	Amount	%DV
Beets	1/2 cup cooked	—
Spinach	1 cup cooked	—
Wheat bran	1/4 cup	—
Quinoa	1 cup cooked	—
Shrimp	3 oz	—
Sweet potatoes	1 medium	—

Safety

Betaine anhydrous is generally well tolerated at supplemental doses. Side effects are uncommon and include mild GI upset and nausea. High doses can cause fishy body odor due to trimethylamine production. Some research suggests betaine may modestly raise total cholesterol or LDL in some individuals; monitor lipids if using long-term at higher doses.

Who should be cautious

Pregnant and breastfeeding women should consult a clinician for supplement doses. People with elevated cholesterol should monitor lipids. Those with kidney disease should consult a clinician given osmolyte effects. People with trimethylaminuria should avoid high doses.

Interactions

Betaine anhydrous may enhance the homocysteine-lowering effects of folate and B12. Lipid-modifying medications should be monitored due to potential cholesterol effects. May affect medications metabolized through methylation pathways.

Frequently asked questions

Is betaine anhydrous the same as TMG?⌄

Yes. Betaine anhydrous is the chemical name; TMG (trimethylglycine) is an alternate name for the same molecule. Both refer to the supplemental methyl donor form.

How does it improve workouts?⌄

Several mechanisms are proposed: cellular hydration via osmolyte effects, support for creatine synthesis via methyl donation, and possibly modulation of muscle signaling pathways. Clinical effects on power and endurance are modest but consistent.

When should I take it for workouts?⌄

Most studies have used a single 2,500 mg dose, often 30 to 60 minutes pre-workout. Daily intake matters more than precise timing for accumulation effects.

Can betaine raise my cholesterol?⌄

Some studies suggest betaine may modestly raise total or LDL cholesterol in some individuals at higher doses (3 g or more daily). Monitor lipids if using long-term.

Should I take it with creatine?⌄

Yes, they are commonly combined. Betaine supports methylation involved in creatine synthesis, and both target performance through different mechanisms. The combination is well tolerated.

References

Wikidata: Betaine anhydrous — Wikidata link

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.