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TB-500 with TB-500 Fragment 17-23

Mechanism-tag overlap and published literature for TB-500 and TB-500 Fragment 17-23, pulled verbatim from each Kalios compound profile. Kalios is a literature reference, not a recommendation.

Mechanism overlap

Mechanism tags are verbatim labels on each compound's profile. Generic tags ("peptide", "small-molecule", "research-chemical") are excluded from this overlap view. Tags are descriptive — not an inference about combined effect.

TB-500 TB-500 FRAGMENT 17-23 2 UNIQUE TAGS 2 UNIQUE TAGS 0 SHARED
TB-500 unique angiogenesissystemic-tissue-repair
Shared none
TB-500 Fragment 17-23 unique actin-binding-domainthymosin-4-active-fragment

Co-administration notes from the literature

Verbatim summary text pulled from each compound's profile data. Researchers studying TB-500 and TB-500 Fragment 17-23 have published these mechanism-level observations. Not a co-administration recommendation.

Evidence level: mechanistic only

Not typically combined — these are alternatives, not a stack. Users generally choose one or the other: fragment for cost-reduced simplified protocol, full-length for broader mechanistic coverage and for the benefit of a larger safety and preclinical database on the parent molecule.

Quick facts

TB-500

RouteSubQ / IM
Half-life~2–3 days
FDA statusCategory 2; RGN-259 Phase 3
WADABanned (S2, since 2011)
Full TB-500 profile →

TB-500 Fragment 17-23

RouteSubQ / IM (research)
Half-lifeNot listed
FDA statusResearch-only; no human trials
WADABanned (S2 — Tβ4-derived)
Full TB-500 Fragment 17-23 profile →

Literature table

Classified references from each compound profile. Click a column header to sort. Click a PMID to open PubMed. Findings are quoted verbatim from each profile's literature_summary; nothing here is added or interpreted.

Year Compound Source Finding
2023TB-500Sosne G, Kim C, Kleinman HK. 0.1% RGN-259 (Thymosin β4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial. Int J Mol Sci. 2023;24(1):554.human trial, Phase 3
2015TB-500Sosne G, Dunn SP, Kim C. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a Phase 2 randomized trial. Cornea. 2015;34(5):491-496.human trial, Phase 2
TB-500ClinicalTrials.gov. A Phase 2 Study on Effect of Thymosin Beta 4 on Wound Healing. NCT00311766.human trial, Phase 2
2010TB-500Ruff D, Crockford D, Girardi G, Zhang Y. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci. 2010;1194:223-229.human trial
1981TB-500Low TL, Hu SK, Goldstein AL. Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations. Proc Natl Acad Sci U S A. 1981;78(2):1162-1166. PMID: 6940133. (Discovery publication.) PMID 6940133mechanism / discovery
2025TB-500WADA. 2025 Prohibited List. Section S2 — Peptide hormones, growth factors, related substances and mimetics. World Anti-Doping Agency. Thymosin β4 and derivatives prohibited since 2011.regulatory / registry
2025TB-500FDA. Bulk Drug Substances That Raise Significant Safety Risks (Category 2) under Section 503A / 503B. FDA.gov. Updated 2025.regulatory / registry
2015TB-500Sosne G, Kleinman HK. Primary Mechanisms of Thymosin β4 Repair Activity in Dry Eye Disorders and Other Tissue Injuries. Invest Ophthalmol Vis Sci. 2015;56(9):5110-5117. PMID: 26241398. PMID 26241398research article
2012TB-500Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. PMID: 22074294. PMID 22074294research article
2011TB-500Smart N, Bollini S, Dubé KN, Vieira JM, Zhou B, Davidson S, Yellon D, Riegler J, Price AN, Lythgoe MF, Pu WT, Riley PR. De novo cardiomyocytes from within the activated adult heart after injury. Nature. 2011;474(7353):640-644. PMID: 21654746. PMID 21654746research article
2010TB-500Sosne G, Qiu P, Goldstein AL, Wheater M. Biological activities of thymosin beta4 defined by active sites in short peptide sequences. FASEB J. 2010;24(7):2144-2151. PMID: 20179146. PMID 20179146research article
2010TB-500Crockford D, Turjman N, Allan C, Angel J. Thymosin beta4: structure, function, and biological properties supporting current and future clinical applications. Ann N Y Acad Sci. 2010;1194:179-189. PMID: 20536465. PMID 20536465research article
2023TB-500 Fragment 17-23Sosne G, Kim C, Kleinman HK. 0.1% RGN-259 (Thymosin β4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial. Int J Mol Sci. 2023;24(1):554. (Full-length parent…human trial, Phase 3
2017TB-500 Fragment 17-23Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105(1):136-143. PMID: 27852613. (Substrate-side adjunct reference.) PMID 27852613mechanism / discovery
2025TB-500 Fragment 17-23WADA. 2025 Prohibited List. Section S2 — Peptide hormones, growth factors, related substances and mimetics. World Anti-Doping Agency. Thymosin β4 and derivatives prohibited since 2011.regulatory / registry
2025TB-500 Fragment 17-23FDA. Bulk Drug Substances That Raise Significant Safety Risks (Category 2) under Section 503A / 503B. FDA.gov. Updated 2025.regulatory / registry
2004TB-500 Fragment 17-23Philp D, Goldstein AL, Kleinman HK. Thymosin beta4 promotes angiogenesis, wound healing, and hair follicle development. Mech Ageing Dev. 2004;125(2):113-115. PMID: 15037010. PMID 15037010research article

Related pair pages

More research context

Frequently asked

Have TB-500 and TB-500 Fragment 17-23 been studied together?

Researchers have published mechanistic-level co-administration discussion of TB-500 and TB-500 Fragment 17-23. No human co-administration trials are catalogued in the Kalios profiles. The pair page lists each compound's classified literature; full citations sit on each individual profile.

What mechanisms do TB-500 and TB-500 Fragment 17-23 share?

TB-500 and TB-500 Fragment 17-23 do not share a specific mechanism tag on their Kalios profiles. They appear on the same pair page because at least one profile lists the other in its co-administration data.

What is the FDA status of TB-500 and TB-500 Fragment 17-23?

TB-500: Category 2; RGN-259 Phase 3. TB-500 Fragment 17-23: Research-only; no human trials. FDA-status text is pulled verbatim from each compound profile. See /fda-pcac-2026.html for the broader FDA Pharmacy Compounding Advisory Committee context.

Where can I find the full research on TB-500 and TB-500 Fragment 17-23?

Full citation lists, dosing tables from the literature, reconstitution data, and the FDA / WADA status are on the individual compound profiles: the TB-500 profile and the TB-500 Fragment 17-23 profile. The Kalios Stack Research Tool hub lists every compound covered.

Last updated: April 2026