Is TB-500 legal? FDA status and US regulatory standing
Current status
Barred from compounding. TB-500 is not FDA-approved and has been placed in a category of bulk substances that licensed pharmacies may not compound (status recorded ). TB-500 / Thymosin Beta-4 is explicitly identified in FDA guidance as not suitable for 503A/503B compounding. Federal compliance risk for providers offering it is high. Patients should understand the legal status before use.
Primary source: www.fda.gov
Federal legal status
FDA approval status
TB-500 is a synthetic peptide derived from thymosin beta-4. It is not FDA-approved and not on the FDA bulk substances lists for compounding. FDA has explicitly listed thymosin beta-4 in guidance indicating it cannot be compounded by 503A/503B facilities.
Compounding pharmacy rules (federal)
TB-500 (thymosin beta-4) is specifically mentioned in FDA guidance as a substance that does not meet the criteria for 503A bulk compounding. It cannot be lawfully compounded by facilities subject to FDA oversight. Some providers offer it under research or investigational frameworks, but this carries significant federal compliance risk.
Also known as
Thymosin Beta-4 · Tβ4
Status history
- TB-500 is not FDA-approved and has been placed in a category of bulk substances that licensed pharmacies may not compound. [source]
About TB-500
TB-500 is the synthetic version of the naturally occurring thymosin beta-4, a protein ubiquitous in human and animal cells. Research has focused on its role in wound healing, angiogenesis, and tissue repair. Human clinical trial data is limited.
Frequently asked questions
- Is TB-500 the same as thymosin beta-4?
- TB-500 is a synthetic peptide fragment derived from thymosin beta-4, specifically the actin-binding domain. The two are often used interchangeably in informal contexts, though they are not identical. FDA guidance on thymosin beta-4 applies to TB-500 in practice.
State-level notes
Compounding and prescribing rules are administered by state pharmacy boards and vary by state. Federal FDA status (above) applies nationwide.
Content review: Regulatory status is sourced from the linked primary records and reviewed by the PeptideBase editorial team. This page is educational — not legal or medical advice. Last reviewed: .