What is betaine?
Betaine, also known as trimethylglycine (TMG), is a natural compound found abundantly in beets, spinach, quinoa, and wheat germ. Chemically, betaine is a glycine molecule with three methyl groups attached.
In the body, betaine serves two primary roles: it acts as a methyl donor in biochemical reactions and as an osmolyte that helps cells maintain water balance under stress conditions.
How betaine works
Betaine participates in several important biochemical processes:
- Methylation: Betaine donates a methyl group to homocysteine, converting it back to methionine. This is an important part of the methylation cycle, which influences DNA expression, protein synthesis, and many other processes
- Homocysteine: By helping convert homocysteine to methionine, betaine supports normal homocysteine levels
- Osmolyte: Betaine acts as an osmolyte, helping cells maintain volume and function under osmotic stress, such as during dehydration or heat stress
- Creatine synthesis: Methylation is connected to creatine synthesis, as S-adenosylmethionine (SAMe) is required for creatine production
Evidence and benefits
Research on betaine spans several areas:
Exercise performance: Multiple studies have examined betaine's effects on physical performance. Some studies show differences in strength and power measures at doses of 2.5 g per day (Lee et al., 2010; Cholewa et al., 2013), but results have been inconsistent across different studies. Currently, betaine supplements do not have a specific EFSA-approved health claim.
Body composition: Betaine's potential effects on body composition in training individuals have been studied. Results are preliminary and study designs have varied.
Homocysteine levels: Betaine's role in homocysteine metabolism is better documented scientifically (Olthof & Verhoef, 2005). Betaine participates in the remethylation of homocysteine to methionine, which is an alternative pathway to the folate-dependent pathway.
Liver health: Betaine has been studied in the context of liver metabolism. These studies are primarily medical and do not pertain to supplement use.
Important: Betaine (TMG) supplements do not currently have a specific EFSA-approved health claim.
How to take betaine
Typical dose: Studies have typically used 1.5-2.5 g per day, often divided into two doses.
Timing: Athletes often take betaine with pre-workout supplements or divided between morning and evening. Specific timing is not critically important.
With or without food: Betaine can be taken with food. The powder form is typically tasteless (may be slightly sour) and mixes well into drinks.
Precautions: Betaine is generally well-tolerated. Consult your doctor if you have kidney problems or take medications. Higher doses may cause digestive upset in some people.
Who should consider betaine?
People who may consider betaine supplementation include:
- Athletes and active individuals looking for potential training support
- People interested in supporting methylation
- Those whose diet is low in beets, spinach, and other betaine-rich foods
- Individuals interested in supporting homocysteine metabolism (consult your doctor)
Frequently asked questions
What is the difference between betaine and betaine HCl? Betaine (TMG) is a methyl donor that participates in the methylation cycle. Betaine HCl is the hydrochloride salt of betaine, used instead for digestive support by increasing stomach acidity. These are products with different purposes and effects.
Can you get enough betaine from food? Betaine-rich foods include beets, spinach, quinoa, and wheat germ. The average dietary betaine intake is about 100-400 mg per day (Craig, 2004), which is lower than doses used in research studies.
Does betaine work well with creatine? Betaine and creatine are often combined, as both support physical performance through different mechanisms. No safety concerns have been identified with this combination.
Does betaine have side effects? Betaine is generally well-tolerated. The most common side effect is digestive upset with large doses. Some individuals may experience a fishy body odor.
How quickly do effects appear? Exercise studies have typically used periods of 2-6 weeks. Betaine's effects tend to be cumulative rather than immediate.
References
- Cholewa JM, Wyszczelska-Rokiel M, Glowacki R, et al. (2013). Effects of betaine on body composition, performance, and homocysteine thiolactone. Journal of the International Society of Sports Nutrition, 10(1), 39.
- Trepanowski JF, Farney TM, McCarthy CG, et al. (2011). The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men. Journal of Strength and Conditioning Research, 25(12), 3461-3471.
- Olthof MR, Verhoef P. (2005). Effects of betaine intake on plasma homocysteine concentrations and consequences for health. Current Drug Metabolism, 6(1), 15-22.
- Craig SA. (2004). Betaine in human nutrition. American Journal of Clinical Nutrition, 80(3), 539-549.
- Lee EC, Maresh CM, Kraemer WJ, et al. (2010). Ergogenic effects of betaine supplementation on strength and power performance. Journal of the International Society of Sports Nutrition, 7, 27.
See also:
Browse training supplements at MaxFit.
Disclaimer
A food supplement is not a substitute for a varied and balanced diet and a healthy lifestyle.
