Legal status · United States
Is Betaine legal in the United States?
Written by Aaron CuhaReviewed Sep 2026
Direct answer
Betaine can be sold in the United States as a supplement or cosmetic ingredient, classified as "Sold as a supplement". That is not drug approval: FDA has not evaluated any health claim, and injectable or "research use only" versions fall outside supplement rules, so that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile.
Betaine in the United States at a glance
| Classification | Sold as a supplement |
|---|---|
| Note | Sold over the counter as TMG. Betaine anhydrous is separately FDA-approved as a prescription medicine for homocystinuria, which is an inherited metabolic disease and not the reason most buyers take it. |
| FDA approval status | Betaine anhydrous is FDA-approved as a prescription medicine for the treatment of homocystinuria. The same molecule is separately sold over the counter as a dietary supplement, usually labelled trimethylglycine or TMG, with no approved indication. |
| Human studies cited | 3 of 5 citations on the profile |
| Reviewed | Sep 2026 |
Classification and note come from the Betaine profile, checked against U.S. Food and Drug Administration (FDA) listings at the reviewed date.
What this means
- 01
Betaine can be sold in the United States as a supplement, food or cosmetic ingredient under the classification above, without drug approval.
- 02
Supplement status means FDA has not evaluated any health claim; manufacturers are responsible for safety and labeling, and quality varies by product.
- 03
Injectable or "research use only" versions are not supplements. That label does not make human use lawful, and injectables fall under medicines rules.
What Betaine is
Six grams a day lowers fasting homocysteine by 20 percent in healthy adults and raises LDL cholesterol by 0.36 mmol/L in the same randomised studies. The trials that lowered homocysteine by other means and then counted heart attacks found nothing: 12,064 survivors, homocysteine down 28 percent, vascular event risk ratio 1.04.
Betaine is the cleanest example in this batch of a compound that does exactly what it says on the bottle, where what it says on the bottle turns out not to be the point. It lowers homocysteine, reliably and dose-dependently.
Mechanism: Betaine donates a methyl group to homocysteine through betaine-homocysteine methyltransferase, regenerating methionine. This is the alternative to the folate and vitamin B12 route, and it runs mainly in liver and kidney, which is why betaine lowers homocysteine even when folate status is adequate.
Regulatory history: Betaine anhydrous is FDA-approved as a prescription medicine for the treatment of homocystinuria. The same molecule is separately sold over the counter as a dietary supplement, usually labelled trimethylglycine or TMG, with no approved indication.
How FDA treats this kind of product
Approves prescription drugs by indication and polices unapproved products, including peptides sold online. Compounding pharmacies may prepare some compounds under a prescription when the FDA places them on a permitted bulk-substances category.
The classification above is the The Longevity Archive reading of U.S. Food and Drug Administration listings for Betaine at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.
Betaine in other countries
Frequently asked questions
Is Betaine legal in the United States?
Betaine can be sold in the United States as a supplement or cosmetic ingredient, classified as "Sold as a supplement". That is not drug approval: FDA has not evaluated any health claim, and injectable or "research use only" versions fall outside supplement rules, so that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile. Note: Sold over the counter as TMG. Betaine anhydrous is separately FDA-approved as a prescription medicine for homocystinuria, which is an inherited metabolic disease and not the reason most buyers take it.
Can I buy Betaine in the United States?
Yes, in supplement or cosmetic form. In the United States Betaine is classified as "Sold as a supplement", so oral, topical or cosmetic products can be sold under supplement rules. Injectable versions and products labeled "research use only" are not supplements and are not approved for human use. Note: Sold over the counter as TMG. Betaine anhydrous is separately FDA-approved as a prescription medicine for homocystinuria, which is an inherited metabolic disease and not the reason most buyers take it.
Is Betaine FDA approved?
No. FDA status: Betaine anhydrous is FDA-approved as a prescription medicine for the treatment of homocystinuria. The same molecule is separately sold over the counter as a dietary supplement, usually labelled trimethylglycine or TMG, with no approved indication.. Current US classification: "Sold as a supplement". On the evidence, 3 human studies are cited on its profile.
Related compounds in the United States
Full research profile
Mechanism, cited studies, FDA status and the full legal summary for Betaine live on its compound profile.
Betaine profileThis page is general information about the regulatory status of Betaine in the United States, current as of Sep 2026. It is not legal advice, and classifications change; check U.S. Food and Drug Administration directly or consult a lawyer for a specific situation. Educational use only. This database summarizes published research. It is not medical advice and contains no dosing protocols or recommendations for personal use. The Longevity Archive has no vendor relationships and does not recommend where to buy anything.