TB-500: Evidence, Legal Status, and Safety
TB-500 is sold as a synthetic fragment related to thymosin beta-4, pitched for the same injury-recovery use case as BPC-157 and often stacked with it. The honesty-critical distinction: the full-length parent molecule has some human safety and wound-healing data, but the synthetic fragment sold as “TB-500” has essentially no dedicated human trial data of its own. It is not FDA-approved for any human use.
Understand what's actually being sold A synthetic peptide fragment modeled on thymosin beta-4, a naturally occurring protein involved in cell migration and wound healing, promoted for the same injury-recovery use case as BPC-157 and often stacked with it.
The name refers to a fragment of the parent protein, not the full molecule that has been studied in humans.
See what belongs to TB-500 versus its parent molecule The parent molecule (full-length thymosin beta-4) has some human data: a completed Phase 1 safety study and Phase 2 wound-closure data. The synthetic fragment sold as TB-500 has essentially no dedicated human trial data of its own; a 2026 scoping review found direct TB-500 evidence limited to a single included study.
This is the single most important honesty point on this page: the human data belongs to the parent molecule, not the product being sold.
Know where it stands Not FDA-approved for any human use; sold as an unregulated research chemical, the same category as BPC-157. On 23 Jul 2026, the FDA's Pharmacy Compounding Advisory Committee recommended TB-500 for compounding, but that recommendation is advisory only: nothing is legal today, and formal rulemaking has not started.
There is no regulatory pathway making TB-500 a legal medical product in its current form.
Know the real risk Same unregulated-manufacturing risk as BPC-157: no purity or sterility guarantee, and no completed human safety trial specific to the synthetic fragment as sold. It is frequently stacked with BPC-157; taking two unapproved, unregulated peptides together compounds unknown risk rather than averaging it out.
Stacking is a popular marketing pattern, not a safety strategy.
Thymosin beta-4, the naturally occurring protein TB-500 is modeled on, has some real human data: a completed Phase 1 safety study in healthy volunteers found intravenous recombinant thymosin beta-4 well-tolerated with no dose-limiting toxicity, and Phase 2 trials showed accelerated wound closure in some skin-wound settings.
View sources
Huberman Lab: Benefits & Risks of Peptide Therapeutics for Physical & Mental Health (TB-500/thymosin beta-4 segment)
2026 scoping review of thymosin beta-4 / TB-500 human evidence
Not medical advice. This page is for education only and is not a substitute for professional medical care. Consult a qualified clinician before changing your health routine.
Editorial disclosure. This protocol is written and fact-checked by the YourProtocol editorial team directly from the primary sources cited below; it is not written or reviewed by any outside expert.
Is this for you
- Anyone considering TB-500 who wants the honest evidence before discussing it with a clinician
- Anyone who has seen BPC-157 and TB-500 marketed together as a “stack”
- Readers who want to know what evidence actually belongs to TB-500 versus its parent molecule
- Readers comparing research chemicals to FDA-approved peptides
Cautions
- Not FDA-approved for any human use; sold as an unregulated research chemical with no purity or sterility guarantee.
- The human data most often cited for “TB-500” actually belongs to the full-length parent molecule, thymosin beta-4, not the fragment sold online.
- Frequently stacked with BPC-157; combining two unapproved, unregulated peptides compounds unknown risk.
- Educational only, not medical advice.