Is TB-500 Legal? FDA Status, Prescription & Compounding
Current regulatory status of TB-500 in the United States: FDA approval, Section 503A compounding eligibility, prescription requirements, and WADA anti-doping status.
Educational content only. This page is compiled from published research for reference and is not medical advice, diagnosis, or treatment. Readers should verify claims against primary sources and consult a qualified healthcare provider before making any health decisions. Full disclaimer.
FDA Regulatory Status
Thymosin beta-4 placed on FDA Category 2 list in late 2023. Not approved for human use. Was previously available through compounding pharmacies.
Source: PeptideMark FDA Peptide Tracker — compiled from FDA.gov bulk substances guidance and 503A nominations.
Prescription & Legal Access
As of late 2023, TB-500 is on the FDA's Category 2 list, prohibiting Section 503A compounding pharmacies from producing it for human use. There is no FDA-sanctioned pathway to obtain TB-500 as a medication, dietary supplement, or compounded drug in the United States. Enforcement against pharmacies that continue to compound it has been signaled by the FDA, though legal challenges are ongoing.
Section 503A Compounding
Section 503A of the Federal Food, Drug, and Cosmetic Act governs which substances compounding pharmacies may use. Substances are placed into one of three categories: Category 1 (eligible for compounding), Category 2 (significant safety concerns — prohibited), or Category 3 (under review).
WADA & Anti-Doping Status
The World Anti-Doping Agency (WADA) lists TB-500 on its Prohibited List, making it banned both in and out of competition for athletes subject to WADA-governed sports. Use by tested athletes will result in an anti-doping rule violation regardless of therapeutic intent.
Frequently Asked Questions
Is TB-500 FDA approved?
No. TB-500 is not FDA approved for any human indication. The FDA placed it on the Category 2 list in late 2023, prohibiting 503A compounding pharmacies from producing it for human use.
Do I need a prescription for TB-500?
TB-500 has no legal retail pathway for human consumption in the U.S. Products labeled "for research only" are not authorized for personal use, and no legitimate U.S. prescription pathway exists outside of FDA-approved indications or authorized clinical trials.
Can compounding pharmacies make TB-500?
No. TB-500 is on the FDA's Category 2 list, which prohibits 503A compounding pharmacies from producing it for human use. The FDA has signaled potential enforcement action against pharmacies that continue to compound it.
Is TB-500 banned by WADA?
Yes. TB-500 is prohibited by the World Anti-Doping Agency (WADA) both in and out of competition. Athletes subject to WADA testing should not use it.
Is it legal to buy TB-500 online?
Products marketed as "TB-500 for research use only" are widely sold online but are not authorized for human consumption. Purchasing these products for personal use may violate FDA regulations and carries significant quality, purity, and legal risk. There is no FDA-sanctioned retail pathway for non-prescription human use.