TMG Benefits: What Trimethylglycine Does, How Much to Take and Safety

TMG (trimethylglycine, also called betaine) is a methyl donor: it hands a methyl group to homocysteine so your body can recycle it into the amino acid methionine. That is its best measured benefit. In a 6-week trial in 76 healthy adults, 1.5 to 6 g of TMG a day lowered fasting homocysteine by 12 to 20 percent compared with placebo, and your body also makes TMG from choline and gets it from foods such as wheat germ, beets and spinach.

Key Takeaways

• Betaine supplies up to 60 percent of the methyl groups the body uses to turn homocysteine back into methionine, through an enzyme called BHMT (Linus Pauling Institute).
• In healthy men and women, 1.5, 3 and 6 g a day for 6 weeks lowered fasting homocysteine by 12, 15 and 20 percent against placebo (Olthof et al., 2003).
• The effect showed up within days and faded within 3 weeks of stopping, so TMG works through steady daily intake (Alfthan et al., 2004).
• The diet already supplies about 830 mg a day, and the European Food Safety Authority found 400 mg a day on top of that safe for the use it reviewed (EFSA, 2017).
• Toasted wheat germ is one of the richest foods, at about 410 mg per 100 g (USDA).

What Is TMG?

TMG is the amino acid glycine with three methyl groups attached, which is where the name trimethylglycine comes from. Chemists and food scientists usually call it betaine. Your liver and kidneys make it from choline, in a one-way conversion: choline can become betaine, but betaine cannot become choline again (Linus Pauling Institute).

TMG has two jobs in the body. It donates methyl groups, and it works as an osmolyte, a small molecule cells use to hold their volume steady under stress, especially in the kidney. Betaine anhydrous, the powder used in sports products, is the same molecule; our betaine anhydrous guide covers the training research, and our TMG ingredient page has the short version.

What Does TMG Do for the Body?

Methylation means moving a methyl group, a tiny carbon unit, from one molecule to another. Your body does it constantly, and TMG feeds one of the main routes:

Step	What happens
1. TMG gives up a methyl group	The enzyme BHMT moves it onto homocysteine
2. Homocysteine becomes methionine	An amino acid your body can use again
3. Methionine becomes SAMe	S-adenosylmethionine, the body's universal methyl donor
4. A second route runs alongside	Vitamin B12 and folate recycle homocysteine through a separate enzyme

Betaine supplies up to 60 percent of the methyl groups needed to recycle homocysteine, and a low folate intake raises the body's demand for it (Linus Pauling Institute). That is why TMG is so often paired with methyl B12; see vitamin B12 benefits for the other half of the cycle. The body also uses methyl groups to make creatine, and our guide to TMG and creatine explains how the two connect.

TMG Benefits: What Studies Measured

The most consistent finding is lower homocysteine in healthy adults. Homocysteine is a marker of how well the methylation cycle is running, which is why it is the standard measure in TMG research.

Lower homocysteine, dose by dose

In a Dutch trial, 76 healthy men and women were split into four groups of 19 and took a placebo or 1.5, 3 or 6 g of betaine a day for 6 weeks (Olthof et al., 2003):

Daily TMG	Fasting homocysteine vs placebo at 6 weeks
1.5 g	12 percent lower
3 g	15 percent lower
6 g	20 percent lower

Betaine also blunted the rise in homocysteine after a methionine load, a test dose of that amino acid, from the very first day at 3 and 6 g, and more so by week 6. The authors concluded that betaine in the range of dietary intake lowers homocysteine.

TMG benefits for women

Women took part in these trials alongside men. In a Finnish study of 34 healthy adults, 23 were women with an average age of about 42, and homocysteine fell as the dose rose to 3 and 6 g a day (Alfthan et al., 2004). These studies did not report a separate effect for women; the methyl donor role is the same for everyone. If you are pregnant or breastfeeding, check with your clinician first.

How Much TMG per Day?

Source	Amount
Typical diet (EFSA estimate)	About 830 mg a day
EFSA safe added amount	400 mg a day on top of diet
Homocysteine trials	1.5 to 6 g a day
Our Enhanced NMN	200 mg per 2 capsules

Sources: EFSA, 2017; Olthof et al., 2003. Our Enhanced NMN includes 200 mg, half the EFSA added amount, as a daily methyl top-up, while the homocysteine trials tested gram amounts. Whatever amount you choose, keep it steady.

TMG in Food

Spinach, beets, wheat and shellfish are good sources of betaine (Linus Pauling Institute). The USDA database lists these amounts per 100 g (USDA):

Food	Betaine per 100 g
Wheat germ, toasted	410 mg
Beets, canned	260 mg
Beets, raw	130 mg
Spinach, frozen, boiled	110 mg
Whole wheat bread	38 mg
Sweet potato, baked	35 mg
Shrimp, canned	23 mg

Intake varies a lot with diet. In the Finnish study, food records showed only about 0.18 g a day (Alfthan et al., 2004), well below the EFSA average, so intake depends heavily on what you eat.

When to Take TMG and How Long It Lasts

Timing is flexible. In the Dutch trial, betaine was taken twice a day with breakfast and dinner, while the Finnish group mixed it into water and drank it during the workday (Alfthan et al., 2004). With a meal is an easy habit, and with your morning supplements works just as well.

As for how long TMG lasts: in a pilot of 6 g a day, homocysteine reached its new lower level within about 5 days. After people stopped, both blood betaine and homocysteine went back to where they started within 3 weeks (Alfthan et al., 2004). The effect holds only while you keep taking it.

Is TMG Safe to Take?

Most people tolerate TMG well, and it is a normal part of the diet. After reviewing the human and animal research, the European Food Safety Authority concluded that 400 mg a day on top of normal food intake is safe for the use it reviewed. Human studies at 4 g a day for up to 6 months found no effect on blood platelets. The only change seen in people came at 4 g a day, 20 times the 200 mg in Enhanced NMN, where blood lipids rose in one group of overweight adults, but not in healthy people and not at 3 g a day (EFSA, 2017).

The 200 mg in our Enhanced NMN is half the EFSA added amount and far below 3 to 4 g. Check with your clinician first if you are pregnant or breastfeeding or take prescription medicine.

TMG With NMN: Where Our Enhanced NMN Fits

TMG is often added to NMN. The liver clears extra nicotinamide by attaching a methyl group to it, turning it into N1-methylnicotinamide, which leaves in urine (NIH ODS), and TMG adds to the body's methyl supply. Our NMN and TMG guide walks through what has been measured, and our NMN dosage guide covers NMN amounts.

Our Enhanced NMN gives you 200 mg of TMG with 750 mg of NMN, 200 mg of resveratrol, 100 mg of pterostilbene and 750 mcg of vitamin B12 as methylcobalamin in every 2 capsules, with ginger extract and vegan capsules, made with third-party tested ingredients. Take 2 capsules in the morning, with or without food. Benefits build with consistent daily use: months 1 to 2 can bring early changes, and 3 months and beyond is where the full benefit builds.

If it is glycine itself you are after, our Melatonin-Free Sleep Powder is coming soon with 3 g of glycine per serving; join the waitlist on its page, and see glycine benefits and our metabolic health hub.

Frequently Asked Questions

What does TMG do for the body?

It donates methyl groups, mainly to turn homocysteine back into methionine, and it helps cells hold their volume steady as an osmolyte.

Is TMG good for you?

For most people, yes. It is a normal part of the diet, and in healthy adults 1.5 to 6 g a day lowered homocysteine, a marker of how well methylation is running.

Is TMG safe to take?

Most people tolerate it well. EFSA judged 400 mg a day on top of diet safe; the only change seen came at 4 g a day, far above the 200 mg in Enhanced NMN.

How much TMG per day?

Food gives about 830 mg a day on average, EFSA judged 400 mg a day on top of that safe, and homocysteine trials used 1.5 to 6 g a day. Our Enhanced NMN adds 200 mg.

How long does TMG last?

Homocysteine settled at a lower level within about 5 days of daily use and returned to where it started within 3 weeks of stopping.

What are the TMG benefits for women?

The same as for men: studies that included women measured lower homocysteine. Check with your clinician first if you are pregnant or breastfeeding.

When should I take betaine TMG?

Any time you will remember. One trial used it twice a day with breakfast and dinner; Enhanced NMN is taken in the morning.

Is TMG the same as betaine?

Yes. TMG, trimethylglycine and betaine anhydrous are the same molecule.

Sources

• Linus Pauling Institute Micronutrient Information Center. Choline (betaine sections). Oregon State University. https://lpi.oregonstate.edu/mic/other-nutrients/choline
• Olthof MR, van Vliet T, Boelsma E, Verhoef P. Low dose betaine supplementation leads to immediate and long term lowering of plasma homocysteine in healthy men and women. Journal of Nutrition, 2003. https://pubmed.ncbi.nlm.nih.gov/14652361/
• Alfthan G, Tapani K, Nissinen K, Saarela J, Aro A. The effect of low doses of betaine on plasma homocysteine in healthy volunteers. British Journal of Nutrition, 2004. https://doi.org/10.1079/BJN20041253
• EFSA Panel on Dietetic Products, Nutrition and Allergies. Safety of betaine as a novel food pursuant to Regulation (EC) No 258/97. EFSA Journal, 2017. https://www.efsa.europa.eu/en/efsajournal/pub/5057
• U.S. Department of Agriculture, Agricultural Research Service. USDA Database for the Choline Content of Common Foods, Release 2, 2008. https://ars.usda.gov/ARSUSERFILES/80400525/DATA/CHOLINE/CHOLN02.PDF
• NIH Office of Dietary Supplements. Niacin: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.