TB-500 (Thymosin Beta-4)
ContestedTissue Repair
Our read of public sources: some pharmacies compound it under a legal theory — a differentiated-formulation argument, or in anticipation of a pending committee recommendation — that no court ruling or final FDA rule has settled either way. We're flagging this as actively debated, not as a green or red light. This is not a legal determination; verify independently before relying on it.
Not legal advice. Every status on this page is our own reading of public FDA guidance, shortage listings, and committee materials — it has not been reviewed by an attorney and is not a legal determination. "Contested" means pharmacies and regulators publicly disagree, not that we're resolving the disagreement. Verify independently, and check with counsel, before relying on any entry here.
Current status
Not currently on the permitted 503A bulk substances list, but the same July 23–24, 2026 PCAC vote (8–6, 1 abstain) recommended adding it for wound healing. FDA staff opposed on the same characterization/immunogenicity grounds. A committee recommendation is not final FDA action — compounding remains outside the permitted list until a rule is issued.
Last changed: 2026-07-24