Quick answer: TB-500 is a synthetic peptide corresponding to a short active region of thymosin beta-4, an actin-binding protein involved in cell migration and tissue repair. The two are related but not identical, and almost all of the supporting evidence comes from cell culture and animal studies rather than human trials. TB-500 is not an FDA-approved drug, is prohibited at all times by the World Anti-Doping Agency, and is generally sold as research-labelled material outside the licensed pharmacy system. Everhuman does not offer TB-500, and this page is a reference rather than an offer.
TB-500 sits in an unusual position: a compound with a real protein behind it, a plausible mechanism, and an evidence base that stops well short of humans. Most people encounter the name in recovery and injury contexts, often paired with BPC-157, and almost always with claims that outrun the studies. Understanding the gap between thymosin beta-4 the protein and TB-500 the marketed peptide explains most of the confusion.
What TB-500 is, and how it differs from thymosin beta-4
Thymosin beta-4 is a naturally occurring protein of 43 amino acids found in most human cells and in relatively high concentration in platelets and wound fluid. Researchers identified a short sequence within it, often written as the actin-binding domain, that appears to account for some of the protein's activity in laboratory models. TB-500 is a synthetic peptide based on that short region, not a copy of the full protein.
Conflating the two is the most common error in TB-500 marketing. Studies performed with full-length thymosin beta-4, including the small number of early-stage human trials that exist, do not automatically transfer to a synthetic fragment with different size, structure and behaviour in the body. When a seller cites thymosin beta-4 research to support TB-500, that substitution is doing quiet work in the argument.
The mechanism described in the literature
Thymosin beta-4 is best characterised as an actin-sequestering protein, meaning it binds monomeric actin and participates in how cells assemble and disassemble their internal scaffolding. Because actin dynamics underpin cell migration, that role connects the protein to processes such as cells moving into an injured area, new blood vessel formation and inflammatory signalling. Laboratory work has also described effects on cell survival and on markers of inflammation.
Plausibility at the mechanism level is genuinely present here, and it is worth acknowledging rather than dismissing. Plausibility is also where most peptide arguments stop, because moving from a cellular mechanism to a measured clinical outcome in people is the expensive part that rarely gets done. The framework in how to read peptide evidence without being misled is useful for keeping those two claims separate.
What the evidence base actually consists of
Evidence for TB-500 and thymosin beta-4 is overwhelmingly preclinical. The published record includes rodent models of cardiac injury, corneal wound repair, dermal wounds and neurological injury, along with a large volume of cell culture work. Those studies report findings that researchers describe as encouraging, and they are the reason the compound continues to be investigated at all.
Human trial evidence is a different picture. Full-length thymosin beta-4 has been examined in a small number of early-phase clinical studies, largely in ophthalmic and dermatological contexts, and those were designed primarily around safety and preliminary signals rather than demonstrating efficacy. For TB-500 specifically, the synthetic fragment sold online, there is no meaningful body of controlled human trial evidence at all.
Stating that plainly matters more than usual with this compound. A reader who searches TB-500 will find pages citing dozens of studies, and nearly every one of those studies is in animals, in cells, or in the full-length protein rather than the fragment. The volume of citations creates an impression of clinical support that the underlying papers do not provide.
Anti-doping status
TB-500 is prohibited in sport. The World Anti-Doping Agency lists it among prohibited growth factors and related substances, banned both in and out of competition, and it appears explicitly by name in the relevant section of the Prohibited List. Athletes subject to testing under WADA-affiliated bodies, including collegiate and professional programmes that adopt those standards, should regard it as a straightforward violation.
Regulatory status and where TB-500 is sold
TB-500 is not an approved drug in the United States, and no FDA-approved product contains it. Material sold under the name is generally offered as a research chemical, labelled not for human consumption, shipped from vendors who operate outside the licensed pharmacy system and outside its quality controls. Purity, identity and sterility in that supply chain are asserted by the seller rather than verified by a regulator.
Supply route is not a technicality with injectable compounds. The difference between a product dispensed by a licensed pharmacy after a clinical evaluation and a vial ordered from a website is laid out in the comparison of research-labelled peptides and prescription products, and it is the practical dividing line in this whole category.
How to think about the claims
Recovery claims for TB-500 typically describe faster repair of soft tissue injuries, reduced inflammation and improved flexibility. Tracing those claims back usually leads to rodent injury models, where the finding is real within the model and says little about a middle-aged man with a chronic tendon problem. Species, injury type, timing and measurement all differ, and each difference is a place the result can fail to carry over.
A reasonable standard is to ask what would have to exist for the claim to be established, then check whether it does. For TB-500 that would mean controlled trials in humans with the specific fragment, measuring the outcome being promised, and those trials do not currently exist. The related reference page on what is actually known about BPC-157 describes a very similar evidence pattern, since the two are usually marketed together.
Frequently Asked Questions
Is TB-500 the same as thymosin beta-4?
TB-500 is a synthetic peptide based on a short active region of thymosin beta-4, not the full 43 amino acid protein. The two are related and are frequently presented as interchangeable in marketing, which is misleading because research on one does not automatically apply to the other. Reading any citation carefully to see which one was actually studied is worth the effort.
Are there human studies on TB-500?
Controlled human trial evidence for TB-500 itself is essentially absent. A small number of early-phase human studies have examined full-length thymosin beta-4 in specific clinical settings, and those were preliminary in design. Nearly everything cited in support of TB-500 for recovery comes from animal models or cell culture.
Is TB-500 banned in sport?
TB-500 is prohibited at all times by the World Anti-Doping Agency and appears by name on the Prohibited List. Athletes tested under WADA rules or by organisations that adopt them should regard it as a clear violation regardless of how a product is labelled. Prohibited status reflects regulatory judgement about performance-affecting activity, not a verdict on safety.
Is TB-500 legal to buy in the United States?
TB-500 is not an FDA-approved drug and is not available as a licensed prescription product. Vendors sell it as research material labelled not for human consumption, an arrangement that exists in a legal grey area rather than a clearly permitted one. The overview of how peptide legality works in the United States explains why that labelling matters.
Why is TB-500 usually sold alongside BPC-157?
TB-500 and BPC-157 are commonly packaged together because both are marketed around soft tissue repair and both have evidence bases built almost entirely on rodent studies. Pairing them is a marketing convention rather than something established by research comparing the combination against either alone. No controlled human evidence supports the pairing.
Does Everhuman offer TB-500?
Everhuman does not offer TB-500. This page exists because the compound is searched heavily and described badly, and an accurate account of the evidence is useful independent of what anyone sells.
The honest summary
TB-500 has a legitimate scientific origin in thymosin beta-4 and a mechanism that makes sense on paper, which is exactly why it is marketed as effectively as it is. Human evidence for the synthetic fragment does not exist in any meaningful form, the compound is prohibited in sport, and the material in circulation comes from vendors outside the licensed pharmacy system. Interesting mechanism, thin human evidence, sold largely outside the regulated system is the accurate description.
Knowing what is unknown is the useful outcome here rather than a verdict for or against. For context on how these compounds are described and what is documented about tolerability, the reference on what is known about peptide side effects continues the same line of thinking. Another repair-associated compound with a similar evidence pattern is copper peptide, also called GHK-Cu.
References
Primary sources for the claims above. Where a study is preclinical, that is stated in the section it supports.
Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert opinion on biological therapy. 2012. PMID 22074294.
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports medicine (Auckland, N.Z.). 2026. PMID 41966639.
Compounded medications are not FDA-approved and are not the same as, nor a substitute for, FDA-approved products. Prescription products require an evaluation by a licensed provider who determines whether a prescription is appropriate. A prescription is not guaranteed. Individual results vary. Everhuman does not provide medical advice; clinical care is delivered by Arora Health.