TB-500 after the October 28 policy: injectable only, single ingredient, still unproven

What changed on October 28

TB-500 is one of six peptides in HHS's October 28, 2026 enforcement discretion policy, alongside BPC-157, MOTS-c, KPV, Semax and Epitalon. Starting October 30, HHS says it does not intend to act against covered compounders that make TB-500 acetate for injection under the policy's conditions.

It follows a July 23, 2026 advisory committee vote recommending TB-500 for the 503A Bulks List, 8 to 6 with one abstention. TB-500 was nominated for wound healing.

The policy's other conditions apply to every one of the six peptides: the ingredient must come from an FDA-registered facility with a valid certificate of analysis made under CGMP, the product may contain only one active ingredient, the only delivery device allowed is an FDA 510(k)-cleared syringe, the label must say it is a compounded drug not for resale, and serious adverse events must be reported to FDA MedWatch.

What it didn't change

It did not approve the peptide; compounded drugs are not FDA approved. It did not add it to the 503A Bulks List, which still requires formal rulemaking. It does not cover "research use only" vials, blends with other peptides, or any route the policy doesn't list. HHS calls the policy interim and says it can revisit it; public comments are open through November 13, 2026.

For TB-500 specifically, the route limit matters: only subcutaneous or intramuscular injection is covered. Oral or topical TB-500, and TB-500 mixed with BPC-157 in one vial, are outside the policy.

What TB-500 is, and what the evidence says

TB-500 is a synthetic fragment associated with thymosin beta-4, a protein involved in cell migration and tissue repair. Most of the interest comes from animal wound-healing research.

In documents for the July 2026 meeting, FDA's reviewers reported no human safety studies for TB-500. There are no controlled human trials showing it speeds recovery from tendon, ligament or muscle injuries. Any provider promising faster healing is ahead of the evidence.

Who should slow down

Anyone in WADA-tested sport: TB-500 is prohibited at all times under the S2 category, and athletes have received multi-year bans. Anyone pregnant or breastfeeding, or with a history of cancer, should raise that with a clinician first, since long-term human safety is unknown.

Ask any provider: Is a licensed clinician reviewing my case? Which state-licensed 503A pharmacy fills it? Is there a certificate of analysis for the ingredient? Is it this peptide alone, with no blend? Is the route one the policy covers? What's the full price, including refills, and how do I cancel? If anything says "FDA approved," treat that as a red flag.