Is TB-500 legal?
Not as a drug. TB-500 has no FDA approval, so selling it for human use breaks federal drug law, and a 'research use only' label does not protect a seller whose site signals human use. It is not a controlled substance, and possessing it is not a federal crime. An FDA advisory committee recommended it for pharmacy compounding in July 2026, but FDA has not acted, so pharmacies still cannot compound it.
DESCRIBES THE LAW · NOT LEGAL ADVICE · NO DOSING INFORMATION
Federal, compounding and sport status
CHECKED 12 OCT 2026Federal status
- Jul 23, 2026 · recommended · 8 yes, 6 no, 1 abstention (law-firm reports) · SOURCE ↗
Sport-body status
What we couldn’t verify
State rules
1 STATESince 1 Jul 2026 Indiana law (IC 16-42-22.5) bars compounding from research-grade or veterinary-grade bulk ingredients outside an IRB-approved study and requires an FDA-registered source with a certificate of analysis. From 1 Jan 2027 medical spas must register with the state medical board. This matters if FDA later allows pharmacies to compound TB-500: in Indiana the ingredient could not be research grade.
- Indiana Senate Enrolled Act 282 (Public Law 136-2026), signed 5 Mar 2026 ↗ · verified Oct 12, 2026
- SEA 282 enrolled text ↗ · verified Oct 12, 2026
In the other states we found nothing that names TB-500; federal law applies.
What changed at the last check
6 CHANGES| Date | Field | Was | Now | Why |
|---|---|---|---|---|
| 12 Oct 2026 | 503A Bulks List status | under pcac review | pcac recommended | Not eligible as of 12 Oct 2026. Removed from Category 2 on 15 Apr 2026; the PCAC recommended it for the Bulks List (wound healing) on 23 Jul 2026. source ↗ |
| 12 Oct 2026 | FDA Category 2 (safety risk) | under pcac review | not on list | FDA's Category 2 page lists it under 'nominated but withdrawn', not in Category 2. source ↗ |
| 12 Oct 2026 | WADA 2026 | prohibited (S2) | prohibited (S2.3) | Named: 'Thymosin-beta4 and its derivatives e.g. TB-500' under S2.3 growth factors. source ↗ |
| 12 Oct 2026 | OH state note | Ohio BOP Feb 2026 peptide compounding guidance directs cessation of TB 500 preparation. | removed | Removed. The entry described a OH action that does not name TB-500; it applied federal-level or class-wide facts by analogy. source ↗ |
| 12 Oct 2026 | IN state note | none | added | Since 1 Jul 2026 Indiana law (IC 16-42-22.5) bars compounding from research-grade or veterinary-grade bulk ingredients outside an IRB-approved study and requires an FDA-registered source with a certificate of analysis. From 1 Jan 2027 medical spas must register with the state medical board. This matters if FDA later allows pharmacies to compound TB-500: in Indiana the ingredient could not be research grade. source ↗ |
| 12 Oct 2026 | PCAC review | pending (vote scheduled) | voted yes | PCAC vote on 2026-07-23: 8 yes, 6 no, 1 abstention (law-firm reports). source ↗ |
Questions
3 ANSWERSIs TB-500 legal in the US?
Not as a drug. TB-500 has no FDA approval, so selling it for human use breaks federal drug law, and a 'research use only' label does not protect a seller whose site signals human use. It is not a controlled substance, and possessing it is not a federal crime. An FDA advisory committee recommended it for pharmacy compounding in July 2026, but FDA has not acted, so pharmacies still cannot compound it.
Can a pharmacy compound TB-500?
Not eligible as of 12 Oct 2026. Removed from Category 2 on 15 Apr 2026; the PCAC recommended it for the Bulks List (wound healing) on 23 Jul 2026. No FDA rule or interim decision has followed. The reported HHS stopgap (Washington Post, 7 Oct 2026) had not been issued as of 12 Oct.
Is TB-500 banned in sport?
Yes. It is prohibited at all times under WADA 2026 class S2.3. Named: 'Thymosin-beta4 and its derivatives e.g. TB-500' under S2.3 growth factors.
Sources
11 DOCUMENTS- FDA approval record
- DEA controlled-substance schedules
- FDA 503A compounding position
- PCAC review, 23 Jul 2026
- FDA warning letter to Warrior Labz SARMs, 12 Jun 2023
- FDA warning letter to US Chem Labs, 7 Feb 2024
- WADA 2026 Prohibited List
- Indiana Senate Enrolled Act 282 (Public Law 136-2026), signed 5 Mar 2026
- SEA 282 enrolled text
- Source for: FDA Category 2 (safety risk)
- Source for: OH state note