Are BPC-157 and TB-500 approved by the FDA?

No. Neither compound is approved by the FDA for any indication. BPC-157 was previously available in compounding contexts but was subsequently removed from the FDA's list of bulk drug substances permitted for 503A compounding after safety and efficacy review.

Has BPC-157 been tested in humans?

Published large-scale human clinical trials are not available. Most of the published research on BPC-157 comes from rodent models of tissue injury and gut pathology, primarily from the research group of Predrag Sikiric and colleagues.

Are these peptides banned in sports?

TB-500 is explicitly named on the WADA Prohibited List under section S2 and is banned at all times. BPC-157 is not currently named on the WADA list by name, but athletes subject to anti-doping rules should consult the annual prohibited list and their sport's specific regulations before using any research peptide.

BPC-157 and TB-500: The Research Behind Healing Peptides

Q: Is TB-500 the same as thymosin beta-4?

Not necessarily. Thymosin beta-4 is a specific naturally occurring 43 amino acid protein. TB-500 is a label applied to research peptides described as either full-length thymosin beta-4 or a shorter synthetic fragment. Without independent analytical testing, a buyer cannot verify which of these a given vial actually contains.

Published: April 10, 2026•Updated: April 10, 2026

Research use only. This article discusses compounds that include approved medications, investigational drugs, and research peptides. Material sold for research is not cleared for human administration and is not a substitute for medical advice.

BPC-157 and TB-500 are two of the most discussed research peptides in recovery and sports medicine circles. Both are marketed informally as tissue repair peptides. This article walks through what the peer-reviewed literature actually shows, where the gaps are, and why the regulatory and anti-doping communities classify them the way they do.

What BPC-157 is

BPC-157 is a synthetic pentadecapeptide, meaning a chain of 15 amino acids. The sequence is derived from a partial fragment of a larger protein called body protection compound, which is present in human gastric juice. Researchers led by Predrag Sikiric at the University of Zagreb have been the most prolific publishers on BPC-157 for decades, with a long series of papers reporting effects in rodent models of tissue injury, gut pathology, and more.

Despite the volume of preclinical publications, well-designed human clinical trials of BPC-157 are scarce. There is no FDA approval for any indication, and there are no large phase 2 or phase 3 trials in peer-reviewed literature.

What TB-500 is

TB-500 is a label applied to research peptides that are described as either full-length thymosin beta-4 or a shorter synthetic fragment of it. Thymosin beta-4 is a small naturally occurring protein found in virtually all human cells. Its main biochemical function is sequestering actin monomers, which influences how the actin cytoskeleton assembles and disassembles during cell movement.

A company called RegeneRx Biopharmaceuticals has conducted early-phase human trials of thymosin beta-4 formulations for specific indications like dry eye and pressure ulcers. These are small trials and are distinct from the TB-500 material sold as a research chemical, which is unregulated and cannot be verified for identity without independent testing.

Proposed mechanisms

Researchers have proposed several mechanisms for both peptides based on in vitro and animal work. Both sets of proposed mechanisms center on tissue repair and the cellular processes that underlie it.

BPC-157 mechanisms (proposed)

Influence on nitric oxide signaling, effects on growth factor expression (VEGF, FGF), interactions with the dopamine and serotonin systems, and effects on angiogenesis and collagen deposition in injured tissue. Most of this evidence comes from rodent models.

TB-500 / thymosin beta-4 mechanisms (proposed)

Sequestration of G-actin monomers, effects on endothelial cell migration and tube formation, influence on inflammatory responses to tissue injury, and reported effects on wound closure in animal models.

What the human evidence actually shows

This is where the gap between popular enthusiasm and clinical evidence is widest. The majority of published BPC-157 research is preclinical and rodent-based. Published large-scale human trials for the tissue repair indications most commonly associated with it in athletic and recovery communities do not exist.

For thymosin beta-4, small trials from RegeneRx and academic partners have explored specific indications like epidermolysis bullosa, dry eye disease, and pressure ulcers. These trials are not equivalent to the tissue repair claims made for research-grade TB-500, and the doses, formulations, and patient populations differ.

An important caveat

Absence of large human trial evidence is not the same as proof that something does not work. It means the evidence base to guide decision-making is not there. For a researcher or clinician, this is a reason to be cautious about extrapolating from rodent studies to human use.

Regulatory and anti-doping status

Both peptides are notable for their regulatory status, which tends to be much more settled than their scientific status.

•Neither BPC-157 nor TB-500 is approved by the FDA for any indication
•The FDA removed BPC-157 from its list of bulk drug substances permitted for compounding under 503A after reviewing available safety and efficacy data
•TB-500 is explicitly listed on the WADA Prohibited List under S2 Peptide Hormones, Growth Factors, Related Substances, and Mimetics, at all times in and out of competition
•BPC-157 is not explicitly named on the current WADA Prohibited List but athletes subject to WADA rules should consult the annual list and their sport's specific regulations
•Multiple national sport anti-doping organizations treat both compounds as unauthorized peptides

The research sourcing question

Research peptides marketed under the BPC-157 and TB-500 names are sold by a range of suppliers. Quality, purity, and even identity vary, and without independent analytical testing there is no practical way for a buyer to confirm what is in a given vial. Published research on analyzed research-chemical samples has repeatedly found discrepancies between labels and content for various peptide products.

From a research sourcing standpoint, this means that supplier reputation, certificates of analysis, lot consistency, and independent testing practices matter more than marketing claims. From a clinical standpoint, these products are not substitutes for FDA-cleared therapeutics and should not be used in place of proper medical care.