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Tb52.5
TB-500 Research
Mostly mechanism / observational
18 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most TB-500 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 1990–2026 with a typical study size of 18 participants.
Based on 18 studies · 5 RCTs · 701 total participants
Confidence
Moderate confidence
By outcome
Vision & eye health
Mostly mechanism / observational3 studies
Wound & ulcer healing
Too few graded studies2 studies
Cardiac repair & heart
Too few graded studies2 studies
Hair & nails
Too few graded studies2 studies
Tumor biology & cancer risk
Too few graded studies1 study
Safety profile
Too few graded studies1 study
Steady research
3 studies in the last 5 years
199020082026
1RCT2010
Ruff D, Crockford D, Girardi G, Zhang Y · Ann N Y Acad Sci (2010)
No plain-language summary recorded for this citation — open the paper to read its abstract.
In plain English: Food and Drug Administration (FDA) and clinical evidence in humans is limited, their use should be guided by careful clinical judgment and ongoing evaluation of emerging evidence.
Luansritisakul C, Chiang MC, Burns SL, Fonseca ACG. · Current pain and headache reports (2026)
Despite their therapeutic potential, evidence regarding the role of regenerative peptides in chronic pain management remains limited.
By synthesizing the available literature, this review aims to provide an evidence-based framework for understanding the potential role of these therapeutic peptides in chronic pain management.
However, because most of these therapies remain unapproved by the U.S.
In plain English: Treatment with thymosin beta 4 (Tβ4) reduces infarct volume and preserves cardiac function in preclinical models of cardiac ischemic injury.
Pipes GT, Yang J. · Vitam Horm (2016)
Review of Tβ4 cardioprotection in preclinical models of cardiac ischemic injury
Reduces infarct size with additional antifibrotic and proangiogenic effects
Effects attributed to SRF-MRTF-G-actin signaling and pleiotropic pathway interactions
In plain English: Tβ4 also accelerated the rate of repair in phase 2 trials with patients having pressure ulcers, stasis ulcers, and epidermolysis bullosa wounds.
Kleinman HK, Sosne G. · Vitam Horm (2016)
Review of Tβ4 in dermal wound repair, with angiogenic and anti-inflammatory activity
Tβ4 accelerated healing across multiple preclinical models, including diabetic and aged animals and burns
Reports Phase 2 trials in pressure ulcers, stasis ulcers and epidermolysis bullosa where Tβ4 accelerated repair
In plain English: Thymosin β4 binds to actin and promotes cell migration, including the mobilization, migration, and differentiation of stem/progenitor cells, which form new blood vessels and regenerate the tissue.
Goldstein AL, Hannappel E, Sosne G, Kleinman HK. · Expert Opin Biol Ther (2012)
Review of thymosin β-4 (Tβ4) as a naturally occurring repair/regeneration peptide released after injury
Tβ4 sequesters G-actin, promotes cell migration and angiogenesis, and reduces inflammation and scarring
Surveys proposed therapeutic uses in skin, eye, heart and brain — largely preclinical with early clinical work
Mechanistic study of the Tβ4–G-actin complex in thrombin-activated human platelets
Actin polymerization on platelet activation tracks loss of the Tβ4–G-actin complex
Supports the model of Tβ4 as a dynamic buffer of polymerizable actin
10In Vitro1990
In plain English: AcSDKP a new regulator of the hematopoietic system can be generated from thymosin beta 4 by a one-step enzymatic cleavage in vitro and in vivo.
Grillon C, Rieger K, Bakala J, Schott D, Morgat JL, Hannappel E, Voelter W, Lenfant M. · FEBS Lett (1990)
In-vitro / in-vivo demonstration that the regulatory tetrapeptide AcSDKP is generated from Tβ4 by enzymatic cleavage
Both Tβ4 and AcSDKP were detected in bone-marrow cells
Identifies a Tβ4-derived signaling product relevant to hematopoiesis and tissue regulation
In plain English: Complete healing occurred after 4 weeks in 6 of the 10 RGN-259-treated subjects and in 1 of the 8 placebo-treated subjects (p = 0.0656), indicating a strong efficacy trend.
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. · Int J Mol Sci (2022)
Randomized, placebo-controlled, double-masked Phase 3 trial of 0.1% RGN-259 (pharmaceutical thymosin β-4) eye drops for persistent epithelial defects in Stage 2-3 neurotrophic keratopathy
Complete healing at 4 weeks in 6/10 treated vs 1/8 placebo (p = 0.0656, trend); significant healing by day 43 (p = 0.0359) with no recurrence in the treated group
Treated subjects had significant improvements in ocular discomfort, foreign-body sensation and dryness; no significant adverse effects
In plain English: At day 56, the RGN-259-treated group (12 eyes) had 35.1% reduction of ocular discomfort compared with vehicle control (6 eyes) (P = 0.0141), and 59.1% reduction of total corneal fluorescein staining compared with vehicle control (P = 0.0108).
Sosne G, Dunn SP, Kim C. · Cornea (2015)
Small multicenter, randomized, double-masked, placebo-controlled Phase 2 trial of 0.1% RGN-259 (thymosin β-4) eye drops in 9 patients with severe dry eye
Significant reductions in ocular discomfort (OSDI) and corneal fluorescein staining vs vehicle at multiple time points, persisting 28 days post-treatment
RGN-259 was safe and well tolerated and met key efficacy objectives (NCT01393132)