TB-500 (Thymosin beta-4 fragment)
Sleep & Recovery · Synthetic peptide
Tier D
Bottom line
Read Off Label grades TB-500 (Thymosin beta-4 fragment) as D (2.9/10) based on preclinical evidence, variable benefit magnitude, and a unknown-high-risk safety profile.
RegeneRx Biopharmaceuticals pursued clinical development; most programs stalled.
Typical use: 2-5 mg subQ weekly (anecdotal) — Not FDA-approved for any indication; Category 2 — compounding prohibited; WADA-banned; veterinary use common in horses.
What this is
RegeneRx Biopharmaceuticals pursued clinical development; most programs stalled. Popular in horse racing (multiple high-profile positive tests) and bodybuilding peptide stacks. Vendors often sell full TB-4 rather than the fragment despite the name. Same FDA Jan 2025 compounding restriction as BPC-157; treat consumer supply as unverified research-peptide exposure.
Mechanism
Fragment (or sometimes full-length) of TB-4, an endogenous actin-sequestering peptide; proposed to promote cell migration, angiogenesis, and wound healing
Dose & route
2-5 mg subQ weekly (anecdotal)
Citations
- https://pubmed.ncbi.nlm.nih.gov/22420962/
- https://pubmed.ncbi.nlm.nih.gov/21415437/
- https://www.fda.gov/media/174456/download
- https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
Links go to the source. If a link is dead or you want something re-checked, let me know.
Common questions
- Does TB-500 (Thymosin beta-4 fragment) work?
- Read Off Label rates the evidence for TB-500 (Thymosin beta-4 fragment) as Preclinical and the benefit magnitude as variable, producing an overall grade of D (2.9/10). RegeneRx Biopharmaceuticals pursued clinical development; most programs stalled.
- Is TB-500 (Thymosin beta-4 fragment) safe?
- TB-500 (Thymosin beta-4 fragment) has a unknown-high risk profile in published human data. Legal status: Not FDA-approved for any indication; Category 2 — compounding prohibited; WADA-banned; veterinary use common in horses. This is not medical advice — see the disclaimer.
- What is the typical dose for TB-500 (Thymosin beta-4 fragment)?
- 2-5 mg subQ weekly (anecdotal)
- How does TB-500 (Thymosin beta-4 fragment) work?
- Fragment (or sometimes full-length) of TB-4, an endogenous actin-sequestering peptide; proposed to promote cell migration, angiogenesis, and wound healing
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.