Peptide
TB-500 (Thymosin Beta-4)
TB-500 (Thymosin Beta-4) is used or studied for may aid recovery and repair and related healing and regeneration goals. Potential benefits and safety depend on indication, formulation, dose, and medical supervision.
In depth
How it works
TB-500 is marketed as a synthetic version of a fragment of thymosin beta-4, a naturally occurring protein. The proposed mechanism centers on binding G-actin, a protein involved in cell structure and movement, which is thought to support the migration of repair cells to injury sites and to dampen inflammatory signaling during healing.
What the research shows
Full-length thymosin beta-4 (not the shorter TB-500 fragment specifically) has been through multiple Phase 2 human clinical trials — an ophthalmic formulation (RGN-259) showed statistically significant improvement over vehicle control in a Phase 2 trial for severe dry eye disease, and separate Phase 2 work has examined dermal wound healing, pressure ulcers, and epidermolysis bullosa wounds.
The muscle and tendon recovery use most discussed in research and fitness communities has not been tested in these controlled trials — it is extrapolated from the same actin-regulation mechanism and animal studies, not directly demonstrated in people for that specific application. Most published research studies thymosin beta-4 broadly rather than the TB-500 fragment specifically sold in the research-compound market.
Safety and who should avoid it
The clinical-trial formulations were reported safe and well tolerated, but those trials used topical/ophthalmic delivery rather than the subcutaneous injections common in research use, so the safety profile does not necessarily transfer directly. Injectable TB-500 is not FDA approved for any indication.
Detail
Overview
TB-500 (Thymosin Beta-4) is used or studied for may aid recovery and repair and related healing and regeneration goals. Potential benefits and safety depend on indication, formulation, dose, and medical supervision.
Benefits, side effects, and protocols
Benefits list
- May aid recovery and repair
Side effects
- Potential immune effects
Vendor protocol
- None listed
Clinical protocol
- None listed
Evidence
- Low
- Gray-market peptide
Regulatory
- Not Fda Approved
Research
Mechanisms
Evidence notes
- Low
- Gray-market peptide
Administration
Research links
Contraindications
- None listed
Components
- None listed
Regulatory data
- Not Fda Approved
Aliases
- None listed
Used in these stacks
Related compounds
Half-life
How long does TB-500 (Thymosin Beta-4) stay in your system?
No human pharmacokinetic study of this compound has been published, so no half-life can honestly be stated. Here is why.
Guides that cover TB-500 (Thymosin Beta-4)
BPC-157, TB-500, CJC-1295 and ipamorelin: what the FDA has actually published about each, why “removed from Category 2” does not mean cleared, and what is still unlawful to compound.
TB-500 is a fragment of thymosin beta-4, and the human trials people cite for it were run on the full-length protein. Here is what each has actually been shown to do.
Anti-doping panels detect peptide hormones and secretagogues; standard workplace panels generally do not screen for them. Legality, detectability, and prohibition are three separate questions.
Terminology on this page
Concepts from the glossary that come up around TB-500 (Thymosin Beta-4).
Frequently asked questions
Is TB-500 the same as thymosin beta-4?
TB-500 is marketed as a synthetic fragment based on thymosin beta-4. Most published clinical research has studied full-length thymosin beta-4 rather than the shorter TB-500 fragment specifically, which is a distinction worth knowing when reading the literature.
Is TB-500 FDA approved?
No. Thymosin beta-4 has been studied in FDA-regulated Phase 2 trials for dry eye and wound healing, but no formulation is FDA approved, and injectable TB-500 sold for research use is not an approved drug.
Does TB-500 have real clinical trial evidence?
Yes, for specific indications — Phase 2 human trials support effects in severe dry eye and certain chronic wounds — but the muscle and tendon recovery use is based on animal studies and mechanistic reasoning, not direct human trials of that specific application.
Educational reference only. Pepperz does not provide medical advice, diagnosis, treatment, prescribing guidance, or dosing recommendations. Sourcing TB-500 (Thymosin Beta-4)? Check your source before you use anything.