What is Thymosin Beta-4 (full length)?

The natural 43-amino-acid actin-binding peptide behind the TB-500 name; tested in human trials for eye, skin-wound and heart conditions.

Thymosin Beta-4 (full length) in the library · Healing & Repair Peptides · Human Trials · What are peptides?

14 registered trials · 9 indexed papers · 128 human / 244 animal studies

From the PeptideWhiz library entry. "As described" sections summarize claims made in the sources; they are not PeptideWhiz endorsements.

What it is

Thymosin beta-4 is described as a 43-amino-acid peptide found in most cells, where it binds actin and controls cell movement. TB-500, which has its own page, is usually a shorter synthetic fragment; many sellers use the two names interchangeably.

Full-length Tβ4 is the form that RegeneRx took into clinical trials as RGN-259 (eye drops) and RGN-137 (topical gel).

Mechanism (as described)

By sequestering G-actin it influences cell migration, and in models it is linked to angiogenesis, reduced inflammation and wound repair (Goldstein et al., 2012).

Evidence (as described)

A randomized, placebo-controlled trial of 0.1% RGN-259 eye drops in neurotrophic keratopathy reported improved healing and comfort (Sosne et al., 2022).
A phase 1 trial of intravenous Tβ4 in healthy volunteers found it well tolerated (Ruff et al., 2010); a European venous ulcer trial suggested faster healing (Guarnera et al., 2007).

Status

Not approved; RGN-259 remains investigational.

Registered human trials (14)

Trial	Phase	Status	Year	Enrolled
Recombinant Human Thymosin Beta 4 for Injection(NL005) for Acute Myocardial Infarction	Phase 2	not yet recruiting	2026	189
Assessment of the Safety and Efficacy of 0.1% RGN-259 Ophthalmic Solution for the Treatment of NK: SEER-2	Phase 3	recruiting	2023	70
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome: ARISE-3	Phase 3	completed	2019	700
A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Myocardial Infarction	Phase 2	withdrawn	2019
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome : ARISE-2	Phase 3	completed	2016	601
Assessment of the Safety and Efficacy Study of RGN-259 Ophthalmic Solutions for Neurotrophic Keratopathy : SEER-1	Phase 3	terminated	2015	18
Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye Syndrome: ARISE-1	Phase 2/Phase 3	completed	2015	317
Comparative Study of Thymosin Beta 4 Eye Drops vs. Vehicle in the Treatment of Severe Dry Eye	Phase 2	completed	2011	9
Safety and Efficacy of Thymosin Beta 4 Ophthalmic Solution in Patients With Dry Eye	Phase 2	completed	2011	72
A Phase 1 Safety Study of the Intravenous Administration of Thymosin Beta in Healthy Volunteers	Phase 1	withdrawn	2008
A Phase 2 Study of the Safety and Efficacy of Thymosin Beta 4 for Treating Corneal Wounds	Phase 2	terminated	2007	12
A Phase 2 Study on Effect of Thymosin Beta 4 on Wound Healing in Patients With Epidermolysis Bullosa	Phase 2	terminated	2006	30
Study of Thymosin Beta 4 in Patients With Venous Stasis Ulcers	Phase 2	completed	2006	72
Study of Thymosin Beta 4 in Patients With Pressure Ulcers	Phase 2	completed	2006	72

Peer-reviewed studies (9)

Paper	Authors	Journal	Year	Type
0.1% RGN-259 (Thymosin ß4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial	Sosne G et al.	International journal of molecular sciences	2022	Randomized Controlled Trial
A first-in-human, randomized, double-blind, single- and multiple-dose, phase I study of recombinant human thymosin β4 in healthy Chinese volunteers	Wang X et al.	Journal of cellular and molecular medicine	2021	Randomized Controlled Trial
Safety and efficacy of autologous thymosin β4 pre-treated endothelial progenitor cell transplantation in patients with acute ST segment elevation myocardial infarction: A pilot study	Zhu J et al.	Cytotherapy	2016	Randomized Controlled Trial
Increases in plasma Tβ4 after intracardiac cell therapy in chronic ischemic heart failure is associated with symptomatic improvement	Choudry FA et al.	Regenerative medicine	2015	Randomized Controlled Trial
Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial	Sosne G et al.	Cornea	2015	Randomized Controlled Trial
Significant decrease in plasma N-acetyl-seryl-aspartyl-lysyl-proline level in patients with end stage renal disease after kidney transplantation	Suzuki Y et al.	Biological & pharmaceutical bulletin	2014	Clinical Trial
A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers	Ruff D et al.	Annals of the New York Academy of Sciences	2010	Randomized Controlled Trial
The effect of thymosin treatment of venous ulcers	Guarnera G et al.	Annals of the New York Academy of Sciences	2010	Randomized Controlled Trial
Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing	Guarnera G et al.	Annals of the New York Academy of Sciences	2007	Randomized Controlled Trial

More cited research

In Vitro Study of Thymosin Beta 4 Promoting Transplanted Fat Survival by Regulating Adipose-Derived Stem Cells (2024, human observational)
A Novel Combination Therapy Tβ4/VIP Protects against Hyperglycemia-Induced Changes in Human Corneal Epithelial Cells (2023, human observational)
The preliminary study of exosomes derived from thymosin beta 4-treated adipose-derived stem cells in fat grafting (2023, human observational)
Thymosin beta 4: A potential novel adjunct treatment for bacterial keratitis (2023, human observational)
Reparative Outcomes in Corneal Infection: Linking Adjunctive Tβ4 Treatment to Nerve Regeneration and Visual Function (2026, animal)
Inhaled exogenous thymosin beta 4 suppresses bleomycin-induced pulmonary fibrosis in mice via TGF-β1 signalling pathway (2025, animal)
Recombinant human thymosin beta 4 improves ischemic cardiac dysfunction in mice and patients with acute ST-segment elevation myocardial infarction after reperfu (2025, animal)
Thymosin Beta-4 Modulates Cardiac Remodeling by Regulating ROCK1 Expression in Adult Mammals (2025, animal)

Conditions researched

Related compounds

FAQ

What is Thymosin Beta-4 (full length)?

The natural 43-amino-acid actin-binding peptide behind the TB-500 name; tested in human trials for eye, skin-wound and heart conditions.

How many registered human trials study Thymosin Beta-4 (full length)?

The PeptideWhiz trial index lists 14 registered trials for Thymosin Beta-4 (full length), the most recent from 2026.

How much published research exists on Thymosin Beta-4 (full length)?

The PeptideWhiz paper index links 9 PubMed papers to Thymosin Beta-4 (full length); by study type, 128 human and 244 animal studies.

Which conditions is Thymosin Beta-4 (full length) researched for?

Eyes: macular degeneration & retinal health, Heart repair: after heart attack, heart failure & enlarged heart, Insulin resistance, prediabetes & type 2 diabetes, Lupus (SLE), Rheumatoid arthritis, Skin, hair loss, wounds & mast-cell/histamine reactivity, Varicose veins.

Research and education only. Not medical advice. No dosing guidance. Data: ClinicalTrials.gov registry and PubMed via the PeptideWhiz index (204,289 studies).