TB-500 Reference
Educational, not medical advice reference for TB-500: Recovery; regulatory status, evidence posture, source review, and schedule notes. Also kno…
Plain English
- What it is
- TB-500 is a lab-made peptide (a short piece of a protein) that is sold for research, not as an approved medicine. It is a fragment of a natural body protein called thymosin beta-4.
- What people use it for
- In the peptide community, people reach for TB-500 hoping it will heal stubborn tendon, ligament, and joint injuries. It is often combined with another peptide, BPC-157, in what users call the healing stack. This use is based on personal reports, not approved treatment.
- What the science shows
- Almost all of the research is on the full natural protein, thymosin beta-4, and was done in animals like mice, not in people. The animal results are mixed. One mouse study found that giving the protein after a heart attack did not regrow heart muscle the way earlier work had suggested, and the authors flagged this as a caution. There are no human studies of the TB-500 fragment that people actually buy.
- The catch
- There is no FDA-approved TB-500 product. The FDA has placed it on a list of substances that may pose significant safety risks when compounded, says it has found no human exposure data for it, and warns it could trigger harmful immune reactions and carry impurities. Because the products sold are a protein fragment and not the full natural protein, what is actually in them is uncertain.
Reference summary
Evidence is mostly extrapolated from thymosin beta-4 animal literature on tissue repair and myocardial injury. Human TB-500-specific clinical evidence is not established.
Regulatory and posture
- Categories
- Recovery
- Aliases
- Thymosin beta-4 fragment, TB4 fragment
- Evidence posture
- preclinical - Commercial claims lean heavily on thymosin beta-4 extrapolation, not direct human TB-500 trials.
- Regulatory status
- No FDA-approved TB-500 drug label. Published literature more often studies full-length thymosin beta-4 than commercial TB-500 vials, so exact product identity matters. On April 16, 2026, FDA published a Federal Register notice (docket FDA-2025-N-6895) scheduling a Pharmacy Compounding Advisory Committee meeting for July 23-24, 2026 to consider TB-500 (free base and acetate), along with BPC-157, KPV, and MOTS-c, for inclusion on the 503A Bulks List. At that meeting the committee narrowly recommended inclusion, against FDA's own reviewers; the recommendation does not bind FDA and TB-500 is not permitted for 503A compounding unless and until FDA completes rulemaking.
- Content review status
- research reference
Selected public sources
- FDA bulk drug substances with significant safety risks
- FDA Federal Register notice (Apr 16, 2026): Pharmacy Compounding Advisory Committee meeting July 23-24, 2026 on bulk drug substances nominated for the 503A Bulks List (incl. BPC-157, TB-500, KPV, MOTS-c on July 23; Emideltide/DSIP, Semax, Epitalon on July 24)
- PubMed: thymosin beta 4 myocardial-injury mouse study
- PubMed: thymosin beta 4 post-MI caution study
Related tools
- Peptide reconstitution calculator - Convert vial mass and BAC water volume into mcg/ml.
- BAC water calculator - Solve BAC water volume for a target concentration.
- Multi-dose vial calculator - Estimate doses per vial and a projected vial-empty date.
- Reconstituted-vial storage window calculator - Estimate a generic usable-window date and days remaining.
- Peptide half-life calculator - Estimate single-dose decay from cited half-life constants.
- Injection-site rotation overview - Public overview of the Pro site-rotation planner.
For research and educational purposes only. Not medical advice.