Tissue repair
TB-500
Also known as Thymosin beta-4 fragment
Synthetic fragment related to thymosin beta-4, studied in animal and lab models of wound healing.
Where the evidence comes from
18 verified records from 5 countries. The number of studies or countries is not proof that TB-500 works or is safe.
Animal study: 11 · Narrative review: 3 · Randomized clinical trial: 4
What is known
Editorial summary not yet written.
What remains uncertain
Editorial summary not yet written.
Conflicting findings
Editorial summary not yet written.
U.S. regulatory status (FDA)
Compound
Product or formulation
FDA status
FDA-approved branded drug
Approved indication
Metara availability (compounded formulation)
Research material (research use only)
Source
Last verified
Notes
Approval applies only to the exact finished drug, formulation and indication. A shared active ingredient does not make a compounded version, blend or other use FDA-approved. Pharmacy or research-material availability is not FDA approval.
International regulatory status
Kept separate from U.S. status. The regulator's country is not the same as where studies took place.
No sourced international decisions recorded yet.
Continue your research
These are two different pathways, not two ways to get the same thing. Neither changes the FDA status shown above.
Clinical care
Available through Metara Health
Explore clinician-guided care and available pharmacy options.
EXPLORE METARA HEALTH →Research materials
Available through BioNex Peptides
Explore research-use materials, lot-specific analytical testing and research documentation.
EXPLORE BIONEX →Limitations
Evidence mostly lab/animal; findings on full-length thymosin beta-4 should not be assumed for the fragment.
Human clinical evidence (4)
Phase IIa Clinical Study of Efficacy and Safety of Injectable Recombinant Human Thymosin Beta 4 in Patients With Acute Myocardial Infarction
Beijing Northland Biotech. Co., Ltd. · ClinicalTrials.gov · NCT05485818
This completed randomized human trial studied the efficacy and safety of injectable recombinant human thymosin beta 4 versus placebo in patients with an acute heart attack. The provided abstract describes the study design but reports no efficacy or safety results.
A Randomized, Double-blind, Placebo-Controlled, Multiple Doses,Dose-escalation，Phase 1b Study of the Safety, Tolerability，Pharmacokinetics and the Potential Immunological Reaction of Recombinant Human Thymosin Beta4 in Chinese Healthy Volunteers
Beijing Northland Biotech. Co., Ltd. · ClinicalTrials.gov · NCT04555850
This completed randomized, placebo-controlled human trial studied recombinant human thymosin beta-4 in healthy Chinese volunteers. It aimed to assess safety, tolerability, how the substance moves through the body, and possible immune reactions, but the provided abstract reports no results.
A Randomized, Double-Blind, Placebo-Controlled, Dose-Response Phase 1 Study of the Safety and Tolerability of the Intravenous Administration of Thymosin Beta 4 and Its Pharmacokinetics After Single and Multiple Doses in Healthy Volunteers
RegeneRx Biopharmaceuticals, Inc. · ClinicalTrials.gov · NCT00743769
This registered human trial planned to compare intravenous thymosin beta-4 with placebo in healthy volunteers, assessing safety, tolerability, and how it moves through the body. The trial was withdrawn, and the provided abstract reports no results.
A Randomized, Double-Blind, Placebo-Controlled, Dose Response Study of the Safety and Efficacy of Thymosin Beta 4 in the Treatment of Patients With Pressure Ulcers
RegeneRx Biopharmaceuticals, Inc. · ClinicalTrials.gov · NCT00382174
This completed randomized, placebo-controlled human trial evaluated thymosin beta-4 applied to the skin in patients with pressure ulcers. It aimed to assess safety, tolerability, and effectiveness, but the provided abstract reports no results.
Systematic & narrative reviews (3)
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
Mendias CL, Awan TM · Sports Medicine · DOI 10.1007/s40279-026-02437-0
This review examined peptide safety and effectiveness for musculoskeletal injuries and athletic performance, drawing on animal findings and available human evidence. Many unapproved peptides showed favorable tissue repair and metabolic outcomes in animals, but rigorous human safety data were scarce and there was potential for serious harm.
Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.
Mayfield CK, Bolia IK, Feingold CL, Lin EH, Liu JN, Rick Hatch GF · The American Journal of Sports Medicine · DOI 10.1177/03635465251357593
This review examined injectable peptides for orthopaedic injuries and sports medicine using laboratory, animal, and human research. BPC-157, TB-4, and TB-500 showed tissue-repair potential mainly in preclinical studies, while human evidence was limited or lacking. The authors concluded that evidence remains insufficient to support clinical use and that further safety and effectiveness research is needed.
The beta-thymosin enigma.
Sun HQ, Yin HL · Annals of the New York Academy of Sciences · DOI 10.1196/annals.1415.021
This review discusses lab research on how beta-thymosins affect actin, a protein that helps cells maintain shape and move. Some cellular effects fit their role in binding individual actin units, while others do not. The authors suggest these varied effects may also involve indirect changes to cell structure and signaling pathways.
Laboratory, animal & other research (11)
Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study.
Biçer O, Adanir O, Güleryüz Y, Balci EC, Dinçel YM, Yenigün MY, Aydin C, Bayrak BY · Joint diseases and related surgery · DOI 10.52312/jdrs.2026.2951
This animal study tested BPC-157, TB-500, and their combination after Achilles tendon injury and repair in rats. Both peptides were associated with improved tendon tissue organization, but only TB-500 significantly increased the force tendons could withstand before breaking; BPC-157's overall tissue scores were not significantly improved. Combining the peptides provided no additional benefit.
The subcommissural organ regulates brain development via secreted peptides.
Zhang T, Ai D, Wei P, Xu Y, Bi Z, Ma F, Li F, Chen XJ, Zhang Z, Zou X, Guo Z, Zhao Y et al. · Nature neuroscience · DOI 10.1038/s41593-024-01639-x
This animal study examined how the subcommissural organ, a brain gland, supports brain development in mice. Removing its cells during embryonic development caused severe fluid buildup and defects in nerve-cell development. Introducing gland-derived peptides—thymosin beta-4, thymosin beta-10, and NP24—substantially reduced these developmental defects.
Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro.
Rahaman KA, Muresan AR, Min H, Son J, Han HS, Kang MJ, Kwon OS · Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · DOI 10.1016/j.jchromb.2024.124033
This animal and laboratory study developed a method to measure TB-500 and its breakdown products in rats, human serum, and enzyme systems, then tested effects in connective-tissue cells. Only the breakdown product Ac-LKKTE significantly improved wound healing compared with controls. The authors suggested that previously reported wound-healing effects may come from this metabolite rather than TB-500 itself.
Deficiency of endothelial sirtuin1 in mice stimulates skeletal muscle insulin sensitivity by modifying the secretome.
Li Q, Zhang Q, Kim YR, Gaddam RR, Jacobs JS, Bachschmid MM, Younis T, Zhu Z, Zingman L, London B, Rauckhorst AJ, Taylor EB et al. · Nature communications · DOI 10.1038/s41467-023-41351-1
This animal and lab study examined loss of Sirt1 in blood-vessel lining cells in male mice and its effects on muscle cells. Although vessel function worsened, skeletal muscle insulin sensitivity improved. Increased release of thymosin beta-4 from Sirt1-deficient vessel-lining cells enhanced insulin signaling in muscle cells.
Recombinant adeno-associated virus carrying thymosin β4 suppresses experimental colitis in mice.
Zheng XY, Lv YF, Li S, Li Q, Zhang QN, Zhang XT, Hao ZM · World journal of gastroenterology · DOI 10.3748/wjg.v23.i2.242
This animal study tested a modified virus carrying the thymosin beta-4 gene in mice with chemically induced colon inflammation. It reduced colon injury, death of intestinal lining cells, inflammatory-cell buildup, and oxidative stress in both models. The authors concluded that this approach could potentially be developed for inflammatory bowel disease.
Adsorption effects of the doping relevant peptides Insulin Lispro, Synachten, TB-500 and GHRP 5.
Judák P, Van Eenoo P, Deventer K · Analytical biochemistry · DOI 10.1016/j.ab.2017.09.003
This laboratory study examined how TB-500 and other peptides stick to glass and plastic surfaces used for testing. Products designed to reduce sticking did not improve peptide recovery in every case. The findings indicate that suitable testing materials depend on the peptide’s physical and chemical properties.
Thymosin beta 4 ameliorates hyperglycemia and improves insulin resistance of KK Cg-Ay/J mouse.
Zhu J, Su LP, Ye L, Lee KO, Ma JH · Diabetes research and clinical practice · DOI 10.1016/j.diabres.2011.12.009
This animal study tested thymosin beta 4 in mice with a model of type 2 diabetes. It improved glucose tolerance and insulin resistance, reduced a marker of long-term blood sugar and triglycerides, and increased adiponectin. These findings were observed in mice, not established in humans.
Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry.
Ho EN, Kwok WH, Lau MY, Wong AS, Wan TS, Lam KK, Schiff PJ, Stewart BD · Journal of chromatography. A · DOI 10.1016/j.chroma.2012.09.043
This animal and laboratory study developed a method to detect TB-500 and its breakdown products in horse urine and blood plasma for doping control. The method successfully confirmed these substances in samples from horses given TB-500. The study evaluated detection, not healing or other health benefits.
Browse worldwide evidence → · Search and filter all TB-500 studies →
Next steps
Profile last reviewed September 26, 2026. Educational content only. Not medical advice, a dosing protocol or a treatment recommendation.