Is TB-500 FDA Approved? What You Need to Know
No. TB-500 is not FDA-approved. But its parent molecule, Thymosin Beta-4, has been studied in multiple human clinical trials for wound healing and cardiac repair. RegeneRx Biopharmaceuticals ran these trials through Phase 2 before pausing development. TB-500 is the synthetic version used in compounded peptide therapy.
In this article
Key Takeaways
- TB-500 is not FDA-approved. It is legally available as a compounded medication with a prescription, prepared by 503A or 503B pharmacies under federal compounding law.
- US patients access TB-500 as a standalone product or as part of the pre-mixed BPC/TB-500 combination through licensed providers and licensed compounding pharmacies.
- The parent molecule Thymosin Beta-4 was studied by RegeneRx Biopharmaceuticals in Phase 2 trials (RGN-137 topical for wound healing, RGN-352 injectable for cardiac repair). Development paused due to company funding constraints, not safety.
- TB-500 was not restricted in the 2024-2026 FDA peptide reclassifications and remains available through compounding pharmacies in 2026.
- Gray market "research chemical" TB-500 is not prescribed, not tested for potency or sterility, and not legal as a therapeutic. PeRx ships it as a ready-to-use subcutaneous injection.
TB-500 FDA Status at a Glance
FDA Approved?
No. Compounded medication.
Clinical Trials?
Parent molecule (Tβ4) reached Phase 2 in humans
Trial Sponsor
RegeneRx Biopharmaceuticals (Rockville, MD)
Indications Studied
Wound healing (topical), cardiac repair (injectable)
Parent Molecule
Thymosin Beta-4, 43 amino acids
Discovery
Allan Goldstein, Albert Einstein College of Medicine, 1966
The Short Answer
TB-500 is not FDA-approved. But unlike many peptides in compounded use, its parent molecule Thymosin Beta-4 has actually been through human clinical trials. RegeneRx Biopharmaceuticals developed two clinical programs: RGN-137 (a topical gel for wound healing) and RGN-352 (an injectable for cardiac repair after heart attack). Both reached Phase 2.
The clinical trials showed positive safety profiles and promising efficacy signals. Development paused due to the company's funding constraints, not because of safety concerns or negative results. Thymosin Beta-4 is one of the most extensively studied peptides in the scientific literature, with research spanning from wound healing to cardiac tissue regeneration to anti-inflammatory effects.
Clinical Trials: What Actually Happened
RGN-137: Wound Healing (Topical)
RegeneRx developed a topical gel formulation of Thymosin Beta-4 for treating chronic and acute wounds, including venous stasis ulcers and epidermolysis bullosa (a rare genetic skin condition). Phase 2 trials showed accelerated wound closure compared to standard care. The topical formulation demonstrated a clean safety profile with no systemic absorption concerns.
RGN-352: Cardiac Repair (Injectable)
The injectable program targeted cardiac tissue repair after acute myocardial infarction (heart attack). The scientific rationale was compelling: Thymosin Beta-4 promotes angiogenesis, cell migration, and anti-inflammatory activity, all critical for cardiac recovery. Phase 1/2 data showed the injectable was safe and well tolerated.
1966
Thymosin Discovery
Allan Goldstein at the Albert Einstein College of Medicine isolates thymosin peptides from the thymus gland. Thymosin Beta-4 turns out to be one of the most abundant intracellular peptides in the human body.
2006
RegeneRx Founded
RegeneRx Biopharmaceuticals begins clinical development of Thymosin Beta-4 for wound healing and cardiac repair.
2013-Present
Development Paused
RegeneRx pauses clinical development due to funding constraints. The company continues to hold the IND filings. Meanwhile, compounded TB-500 becomes widely used in peptide therapy for recovery applications.
1980s-2000s
Mechanism Elucidation
Researchers discover Tβ4's role in actin sequestration, cell migration, angiogenesis, and wound healing. Hundreds of studies characterize its biological functions across multiple tissue types.
2008-2012
Phase 2 Trials
RGN-137 (topical) enters Phase 2 for wound healing. RGN-352 (injectable) enters Phase 1/2 for cardiac repair. Both show positive safety and preliminary efficacy signals.
Why TB-500 Matters for Recovery
TB-500's value in recovery comes from its unique mechanism: it reorganizes the actin cytoskeleton inside cells, enabling them to migrate to injury sites. It also stimulates angiogenesis (new blood vessel formation), reduces inflammatory cytokines, and promotes organized collagen deposition over fibrotic scarring. This combination of cell migration, blood supply, and anti-inflammation is why practitioners use it for musculoskeletal recovery.
Importantly, Thymosin Beta-4 is endogenous. Your body already produces it. It is present in virtually every cell and tissue, with high concentrations in wound fluid, blood platelets, and white blood cells. TB-500 therapy supplements a peptide your body already uses for repair.
Current Regulatory Status
TB-500 is available as a compounded medication under federal pharmacy compounding law. It requires a prescription from a licensed provider and must be prepared by a licensed 503A or 503B pharmacy. PeRx offers TB-500 both as a standalone product and as part of the pre-mixed BPC/TB-500 combination.
| TB-500 (Compounded) | Thymosin Beta-4 (Clinical) | |
|---|---|---|
| FDA Approved | No | Phase 2 reached, development paused |
| Molecule | Synthetic Tβ4 (43 amino acids) | Same molecule, pharmaceutical grade |
| Route | Subcutaneous injection | Topical (RGN-137) or injectable (RGN-352) |
| Availability | Compounding pharmacy with prescription | Not commercially available |
| Human Safety Data | Practitioner experience + clinical trial safety data for Tβ4 | Phase 1/2 safety data (well tolerated) |
Frequently Asked Questions
Related Guides
Continue reading about peptides and protocols that pair well with this guide.
BPC + TB-500 2026: Tissue Repair Combo Guide
One peptide sends the repair signals. The other moves the construction crew into position and builds the blood supply to keep them working. BPC-157 and TB-500 were discovered decades apart, on different continents, for completely different reasons. Practitioners started combining them because the science pointed to an obvious fit: they cover non-overlapping phases of the same healing process. This is the most widely used peptide combination in injury recovery.
Why We Pair BPC-157 With TB-500 (and When BPC-157 Alone Is Enough)
BPC-157 and TB-500 are both repair peptides, but they cover different ground. BPC-157 works fast and focal, strongest at a specific injury and in the gut. TB-500 works broad and systemic, moving repair cells across the whole body. The pairing is not automatic. Here is how a provider decides whether you need both, or whether BPC-157 on its own does the job.
Pinealon, PE-22-28 & Selank Guide (2026)
Three peptides, three layers of brain support. Pinealon restores sleep architecture through pineal gland regulation. PE-22-28 drives neurogenesis by blocking the TREK-1 potassium channel. Selank calms anxiety through GABA modulation without sedation or dependence. Together they rebuild, grow, and protect neural tissue from three independent angles.
Ready to get started?
Pharmaceutical-grade TB-500 or the pre-mixed BPC/TB-500 combination. Prescribed by a licensed provider, shipped to your door, fully reconstituted and ready to use.
Medical Disclaimer
The information provided on this website, including all articles, guides, and educational content, is for informational and educational purposes only and is not intended as medical advice, diagnosis, or treatment. Nothing on this site should be construed as a substitute for professional medical advice from a qualified healthcare provider.
The majority of peptides discussed on this site are not approved by the U.S. Food and Drug Administration (FDA) for the indications described. They are classified as bulk drug substances and are available only through a licensed prescribing provider and compounding pharmacy. All treatments require a valid prescription and provider oversight.
The majority of published research on peptide therapies has been conducted in preclinical (animal) models. While early human data is encouraging, comprehensive clinical trial data remains limited for most peptide compounds. Individual results may vary significantly based on health status, injury type, and other factors. No specific outcomes are guaranteed.
Certain peptides discussed on this site are classified as prohibited substances by the World Anti-Doping Agency (WADA) and are banned by major sports organizations including the NFL, NCAA, UFC, NBA, MLB, NHL, and PGA. If you are subject to anti-doping testing, consult your governing body before considering any peptide therapy.
Statements on this website have not been evaluated by the Food and Drug Administration. Products and therapies discussed are not intended to diagnose, treat, cure, or prevent any disease.
© 2026 Wellness MD Group PC DBA PeRx. All rights reserved.