What is TB-500?
TB-500 is a synthetic peptide. It copies a short, active section of thymosin beta-4 (often written Tβ4), a protein your body makes in almost every type of cell. Thymosin beta-4 helps cells build actin, part of the internal scaffolding cells use to change shape and move.
That's the key idea behind the interest in TB-500: when tissue is damaged, cells have to move into the area to rebuild it, and thymosin beta-4 is involved in that movement.
TB-500 vs. thymosin beta-4
This is the part most online articles skip. Thymosin beta-4 is the full, 43-amino-acid natural protein. TB-500 is a small synthetic fragment of it. Most published research, including the few small human trials on wound and eye healing, used the full thymosin beta-4 protein, not the TB-500 fragment. So when you read that "TB-500 is proven to heal," check what was actually studied. Results from the full protein don't automatically carry over to the fragment.
What has it been studied for?
- Tissue repair: lab and animal studies look at muscle, tendon, skin, and wound healing.
- Cell movement: research looks at how thymosin beta-4 helps cells migrate to where they're needed.
- Blood vessel formation: early research looks at its role in forming new small blood vessels.
Most of this work is preclinical, meaning it was done in the lab or in animals. Large, well-designed human studies of TB-500 itself don't exist yet.
TB-500 and BPC-157: the Wolverine stack
TB-500 is often paired with BPC-157, a combination people call the "Wolverine" stack. The reasoning is that each has been studied for a different part of tissue repair. There's very little research on the two used together, so whether a combination makes sense is a decision for you and your provider. Read more in The Wolverine Stack, Explained.
Who should be careful
- Athletes in tested sports: thymosin beta-4 and its fragments, including TB-500, are on the World Anti-Doping Agency's prohibited list.
- Anyone with a current or past cancer diagnosis: because thymosin beta-4 is studied for its role in cell growth and new blood vessels, talk to your provider first.
- Pregnant or nursing women, and anyone taking other prescription medications.
Is TB-500 legal and FDA-approved?
TB-500 is not FDA-approved to treat any condition. It's widely sold online as a "research chemical," which means no prescription, no provider, and no way to know what's in the vial. At Onus, peptides are sourced from a U.S.-based manufacturer and prescribed only after a consultation with a licensed provider.
How TB-500 works at Onus
- Free consult: we review your history, goals, and labs where appropriate.
- Personal plan: your provider decides if TB-500 fits, on its own or in our Wolverine Blend, and sets the dose and schedule.
- Guided start: a nurse or nurse practitioner walks you through it, in store or by telehealth.
- Check-ins: we track how you're doing and adjust.
Learn more on our TB-500 page, or book a free consultation at any of our 7 Colorado locations.
A note on the evidence
This article is general information, not medical advice. TB-500 is not FDA-approved to treat any condition, research is still early, and individual results vary. No outcome is guaranteed. A licensed provider looks at your history, medications, and goals before recommending any peptide.