TB-500 Where to Buy

What a verifiable TB-500 source shows

A 2026 review places TB-500 in a gray market of peptides sold largely outside regulatory oversight. In that market, the label alone tells a buyer little. A verifiable source publishes an independent third-party batch report with three checkable items: the HPLC purity percentage, the measured quantity in the vial, and a lab verify key that anyone can enter on the lab's own site to confirm the report is genuine. These three items describe the batch. They say nothing about what the peptide does in a living body.Review · PMID 41966639

Purity matters partly because the molecule is so variable. Researchers analyzing human tissue and fluid samples with high-resolution chromatography methods identified multiple forms of thymosin beta-4, including C-terminal truncated forms, oxidized sulfoxide forms and acetylated forms. With that many related variants possible, the purity percentage is a meaningful number.Human observational · PMID 26095945

TB-500 and thymosin beta-4 are not identical

Thymosin beta-4 is a naturally occurring peptide 43 amino acids long. It binds actin, the protein that drives cell movement, and platelets, macrophages and other cells release it after tissue injury. A 2026 narrative review lists TB-500 separately, as a thymosin beta-4 fragment, next to full-length thymosin beta-4.Human RCT · PMID 20536470Review · PMID 22074294Review · PMID 41966639

That distinction shapes how the literature should be read. Every human trial in this evidence set tested synthetic or recombinant full-length thymosin beta-4, or cells exposed to it, not TB-500. Animal work also suggests that activity can sit in parts of the molecule: a 2023 review reports that the N-terminal fragment Ac-SDKP carries much of the anti-fibrotic activity seen in animal models of liver, lung, heart and kidney fibrosis.Review · PMID 36580759

Human phase 1 trials: tolerability and blood levels

In a 2010 randomized, placebo-controlled phase 1 trial, 40 volunteers without known disease were split into four cohorts of 10. Each cohort was given synthetic thymosin beta-4 intravenously at one of four ascending exposure levels spanning a 30-fold range, first once and then repeatedly over 14 days. Adverse events were infrequent and mild or moderate. No serious adverse events and no exposure-limiting toxicities were reported. Blood levels rose in proportion to exposure level, and half-life lengthened in the higher groups.Human RCT · PMID 20536472

A 2021 first-in-human, randomized, double-blind trial tested recombinant human thymosin beta-4 in 54 volunteers across seven single-exposure groups, plus 30 volunteers in three repeated-exposure groups over 10 days, with 28 days of observation. Adverse events were mild to moderate, with no serious adverse events. Peak concentration and total exposure rose with each higher group, and there was no obvious accumulation with repeated exposure.Human RCT · PMID 34346165

Both trials were systemic: the peptide entered the bloodstream. The wound and eye trials below applied thymosin beta-4 locally, to skin or to the eye surface. Neither phase 1 trial measured a clinical endpoint. Both were designed to support later research in heart ischemia.Human RCT · PMID 20536472Human RCT · PMID 34346165

Wound, eye and heart trials in people

In a phase 2 double-blind, placebo-controlled trial at eight European sites, 73 adults with venous stasis ulcers were randomized to topical thymosin beta-4 or placebo. The adverse-event profile was comparable to placebo. Complete wound closure within 3 months was reported in about 25% of participants, mostly those with small to moderate wounds. The published design described 84 days of exposure, 14 days of follow-up and 3:1 randomization.Human RCT · PMID 20536470Human RCT · PMID 17495250

In a 56-day phase 2 randomized, double-masked trial of 9 adults with severe dry eye, thymosin beta-4 eye drops were compared with vehicle. At day 56, ocular discomfort was 35.1% lower and total corneal fluorescein staining was 59.1% lower in the active group (12 eyes) than in the vehicle group (6 eyes). Tear film breakup time and tear volume also favored the active group.Human RCT · PMID 25826322

Heart data in people are indirect. In a 2016 randomized pilot trial of 10 adults after ST-elevation heart attack, five received their own endothelial progenitor cells pre-exposed to thymosin beta-4 and five received unexposed cells. At 6 months, 6-minute walk distance rose by 75.7 meters versus 38.2 meters, a 37.5-meter difference. In a cell-transplantation study of 27 adults with chronic ischemic heart failure, plasma thymosin beta-4 rose 24 hours after the procedure, and larger rises tracked with a milder symptom class.Human RCT · PMID 27288307Human RCT · PMID 26022762

Animal and cell findings: tendon, inflammation, fibrosis and brain

For tendon and other musculoskeletal tissue, a 2026 scoping review of six peptides, including TB-500, found that 67% of publications used animal models, most often rats. Animal effects on tendon, muscle, bone and ligament were promising but variable, and human data showed modest changes at best. In one retrospective chart review of knee pain, 3 of 4 people given BPC-157 together with thymosin beta-4 reported relief, with no control group and no standardized measurement tools.Review · PMID 42578445Human observational · PMID 34324435

Animal results on immune signaling vary by tissue. In mice with chemically induced colitis that received thymosin beta-4 by gene delivery, myeloperoxidase activity, immune cell infiltration and colon injury scores fell relative to controls. In a mouse dry eye model, cytokine levels and CD4+ T cell counts fell relative to controls in mice given topical recombinant thymosin beta-4, alongside lower NF-κB activation. Pointing the other way, a 2025 study linked high thymosin beta-4 in the colonic mucus of people with irritable bowel syndrome to gut barrier disruption, and rats lacking the gene resisted stress-induced barrier changes.Animal study · PMID 28127198Animal study · PMID 35628276Animal study · PMID 41278163

In mice with chemically induced liver fibrosis that received thymosin beta-4 by gene delivery, collagen deposition and pro-fibrotic signaling were lower than in controls, alongside reduced TGF-β receptor II. In mice and rabbits with limb ischemia, thymosin beta-4 gene transfer raised capillary density and perfusion, and the effect disappeared when the PI3K/AKT pathway was blocked.Animal study · PMID 29972714Animal study · PMID 25652683

Brain research is early. In Alzheimer-model APP/PS1 mice, thymosin beta-4 over-expression was linked to less amyloid accumulation and higher memory-test scores. Brain organoids grown from human stem cells carrying familial Alzheimer mutations showed reversal of neurodevelopmental deficits and amyloid formation after thymosin beta-4 was added. In cultured human brain endothelial cells, pre-exposure reversed low-oxygen damage to barrier components through S1PR1 signaling. Many of these animal studies used gene delivery, not the peptide itself.Animal study · PMID 34183019In vitro · PMID 40816274In vitro · PMID 41326489

How thin the evidence is

No study in this evidence set tested TB-500 itself in people. A 2026 orthopaedic review describes a lack of clinical trials for TB-500 and similar peptides despite promising preclinical studies. The scoping review concluded that musculoskeletal claims remain unsubstantiated by current human trials. A separate 2026 review notes that rigorous human safety data for gray-market peptides are scarce, that serious harm is possible, and that placebo effects amplified by social media may shape user reports.Review · PMID 41490200Review · PMID 42578445Review · PMID 41966639

The human thymosin beta-4 trials that do exist are small, with 9 to 73 participants, and short, running from 2 weeks to 6 months. Any compound's research value depends on what is actually in the vial, which is why batch testing matters.Human RCT · PMID 25826322Human RCT · PMID 20536470Human RCT · PMID 20536472Human RCT · PMID 27288307

The studies at a glance

Human and animal studies of thymosin beta-4 (no study tested TB-500 itself)

Frequently asked questions