SYS · ONLINE│PASS · 63.0%
Open Assay
Independent Testing / Est. 2026
BATCH04·26·B
PASS63.0%
N27
Peptides›Healing›TB-500

TB-500

/ Naturally occurring 43-amino-acid peptide (Tβ4); TB-500 often used commercially as a synonym though technically refers to a synthetic fragment
TIER 2 · TranslationalN = 0 · TESTING PENDINGLAST REVIEW 2026·04·20

ALIAS · Thymosin Beta-4 · Tβ4

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0
Samples
0
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Research use onlyAny dose figures below describe what specific cited studies used, reported factually. Nothing on this page is guidance for human use.READ FIRST →

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§ A · Identity
Primary sequence— sequence not captured —
MW · —CLASS · Naturally occurring 43-amino-acid peptide (Tβ4); TB-500 often used commercially as a synonym though technically refers to a synthetic fragmentCATEGORY · Healing

Phase I intravenous safety (Ruff 2010) and Phase II ophthalmic efficacy (Sosne 2010) in humans, but no systemic musculoskeletal human trial data exists. Nomenclature confusion between full-length Tβ4 and fragment TB-500 is widespread.

§ B · Mechanism of action

Thymosin Beta-4 is a naturally occurring 43-amino-acid peptide. TB-500 is often used commercially as a synonym, though technically it refers to a synthetic fragment. Tβ4 sequesters G-actin monomers, regulating cytoskeletal dynamics and cell migration. Reported mechanisms include promotion of angiogenesis via VEGF upregulation, anti-inflammatory effects through reduced NF-κB activation, and support for epithelial and endothelial migration during wound healing.

§ C · Human clinical evidence

More substantial than BPC-157. Completed Phase I intravenous safety trials (RegeneRx programs) and a Phase II ophthalmic trial (dry eye, Sosne 2010). No Phase III approvals. Systemic injectable use for musculoskeletal indications has no rigorous human trial evidence.

§ D · Primary literature
PubMed16112614Goldstein AL et al. — Thymosin β4: actin-sequestering protein moonlights to repair injured tissues · Trends in Molecular Medicine · reviewFoundational mechanistic review of Thymosin Beta-4 as an actin-sequestering peptide that modulates cell migration, angiogenesis, and wound healing.Limitations: Narrative review; does not establish clinical efficacy.2005
DOI10.1097/ICO.0b013e3181c11155Sosne G et al. — Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, phase II clinical trial · Cornea · human-phase-2Randomized placebo-controlled Phase II trial reported improvement in ocular symptoms with topical Thymosin Beta-4 in dry-eye patients.Limitations: Small sample size; short duration; topical ophthalmic formulation only.2010
PubMed20875041Ruff D et al. — A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers · Annals of the New York Academy of Sciences · human-phase-1Phase I safety trial in 40 healthy volunteers found no serious adverse events at tested intravenous doses (42-1260 mg single dose).Limitations: Phase I safety only; does not establish efficacy in any indication.2010
§ F · Safety signal

Phase I intravenous study (Ruff 2010) reported no serious adverse events across tested doses in 40 healthy volunteers. Ophthalmic trials report mild transient irritation. Long-term systemic safety unknown. WADA-banned for competitive athletes (S2 class).

§ H · Regulatory status

Regulatory status

FDA status:
Not FDA-approved
Compounding:
503A Category 2 — do-not-compound pending review
§ I · Notable gaps and controversies

Nomenclature confusion between endogenous Tβ4 (studied in legitimate pharmaceutical development) and "TB-500" sold online (often unverified purity; fragment vs. full-length unclear). Tendon and ligament healing claims rest on rodent data; no human RCT exists for systemic musculoskeletal use.