Journal September 17, 2026 6 min read

How to Reconstitute TB-500 (Thymosin Beta-4)

TB-500 is a synthetic 17–23 fragment of thymosin beta-4. This page covers its identifiers, the actin-sequestration pathway it is studied against, and the clinical and preclinical research record — including where the evi

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TB-500 is the synthetic 17–23 fragment of thymosin beta-4 (Tβ4), a naturally occurring actin-binding peptide. In the research literature the fragment is also referred to as thymosin beta-4 17-23, Tβ4(17-23), and, in some commercial and review contexts, as TB-4 or TB-500 [10]. It belongs to the thymosin family of actin-sequestering peptides, and the work around it centres on the actin-sequestration pathway — specifically the peptide's interaction with monomeric G-actin and its downstream association with cell migration and tissue-repair signalling [10].

Reconstitution itself is a laboratory procedure: the lyophilised peptide is dissolved in a suitable solvent to a defined working concentration before use in an assay or model system. The evidence block below does not specify a reconstitution protocol, solvent, or concentration for TB-500, and no such values are given here. What the evidence does provide is the research context — a set of clinical trial records and preclinical reports that describe how the peptide and its parent protein have been studied.

Research Studies

TB-500 and cardiovascular biomarkers in stable ASCVD

A Phase 1/2 trial evaluated the safety and tolerability of TB-500 — described in the record as a 17–23 fragment of thymosin beta 4 — versus placebo in adults with stable atherosclerotic cardiovascular disease (ASCVD). Exploratory endpoints assessed vascular function and inflammation biomarkers [1]. This is a clinical record in a human population with stable ASCVD; it is not a reconstitution study and does not report a preparation method.

Recombinant human thymosin beta 4 and infarct size after STEMI

A Phase IIc trial of recombinant human thymosin beta 4 injection (NL005) was designed to assess whether the agent reduces permanent heart muscle damage in people who had experienced ST-segment elevation myocardial infarction (STEMI) and had been treated with emergency percutaneous coronary intervention (PCI). The primary question concerned infarct size measured by cardiac magnetic resonance (CMR) at 90 days, alongside safety monitoring [2]. The population is post-STEMI adults; the outcome measure is imaging-based infarct size.

Thymosin beta 4 and neurotrophic keratopathy (SEER-2)

The SEER-2 study compared 0.1% RGN-259 ophthalmic solution to placebo for the treatment of neurotrophic keratopathy (NK) [3]. This is a topical ophthalmic formulation, not a reconstituted injectable, and the population is patients with NK. It is included here because it is part of the thymosin beta-4 clinical record, not because it informs reconstitution.

Thymosin beta 4 dose groups in acute myocardial infarction (NCT05984134)

A multicentre randomised double-blind placebo-controlled trial assigned 90 participants to placebo, 0.5 µg/kg, or 1.0 µg/kg in a 1:1:1 ratio. Subjects received the trial drug or placebo intravenously within 12 hours and on days 2 to 7 after PCI, with observation at 90 days [4]. The record specifies dose groups and route; it does not describe reconstitution.

Thymosin beta 4 dose groups in acute myocardial infarction (NCT05485818)

A separate multicentre randomised double-blind placebo-controlled trial planned to assign 60 eligible subjects to low-dose (0.25 µg/kg), medium-dose (0.5 µg/kg), high-dose (2.0 µg/kg), or placebo in a 1:1:1:1 ratio. Dosing was intravenous once daily on days 2 to 7, at 12 hours and 4 hours after PCI, with observation at 90 days [5]. As above, the record reports dose and schedule, not preparation.

RGN-352 injectable thymosin beta 4 in acute myocardial infarction

A study of RGN-352 (thymosin beta 4 injectable solution) evaluated safety and tolerability of two active doses in patients with acute myocardial infarction receiving PCI angioplasty with or without stent placement. Approximately 75 subjects were to be randomised to 1200 mg, 450 mg, or placebo, administered intravenously by IV push daily for the first 3 consecutive days and weekly for 4 more weeks [6]. The record gives absolute milligram doses rather than weight-adjusted doses, which distinguishes it from the µg/kg trials above.

RGN-259 ophthalmic solution in dry eye (ARISE-3)

The ARISE-3 study compared RGN-259 ophthalmic solution to placebo for the signs and symptoms of dry eye [7]. The population is dry-eye patients and the route is topical ocular. It sits alongside the NK trial as part of the ophthalmic thymosin beta-4 programme.

Thymosin beta 4 in healthy volunteers (Phase 1b)

A Phase 1b study evaluated the safety, tolerance, pharmacokinetics, and potential immunological reaction of single intravenous recombinant human thymosin β4 (NL005) or placebo at 0.5, 2.0, and 5.0 µg/kg in Chinese healthy volunteers. Thirty volunteers were to be randomly assigned to one of three groups to receive NL005 or placebo for 10 consecutive days [8]. This is the only record in the evidence block that describes a healthy-volunteer population, and it is the closest the clinical record comes to a pharmacokinetic characterisation of the peptide.

TB-500 and Achilles tendon healing in rats

A study evaluated the effects of BPC-157, synthetic thymosin beta-4 (TB-500), and their combination on Achilles tendon healing using biomechanical, histopathological, histochemical, and immunohistochemical analyses in a rat model. Thirty-two male Sprague-Dawley rats were used [9]. This is an animal-only study; no human tendon-healing data are reported in the evidence block.

Comparison of the clinical records

The table below summarises the human clinical records in the evidence block by population, route, and reported dose or formulation. It is a comparison of study designs, not of outcomes.

Record	Population	Route / formulation	Dose or concentration reported
[1]	Stable ASCVD	Not specified in record	Not specified in record
[2]	Post-STEMI, post-PCI	Injection (NL005)	Not specified in record
[3]	Neurotrophic keratopathy	Ophthalmic solution	0.1% RGN-259
[4]	Acute myocardial infarction	Intravenous	0.5 µg/kg; 1.0 µg/kg
[5]	Acute myocardial infarction	Intravenous	0.25 µg/kg; 0.5 µg/kg; 2.0 µg/kg
[6]	Acute myocardial infarction, post-PCI	Intravenous push	450 mg; 1200 mg
[7]	Dry eye	Ophthalmic solution	Not specified in record
[8]	Healthy volunteers	Intravenous	0.5 µg/kg; 2.0 µg/kg; 5.0 µg/kg

TB-500 in regenerative-medicine and sports-medicine reviews

A narrative review of regenerative peptides relevant to chronic pain management covered collagen peptides, BPC-157, thymosin beta-4 (TB-4), TB-500, GHK-Cu, and growth hormone-related peptides, among others [10]. A separate review of peptide supplements in sports medicine noted that the peptide supplement market has grown rapidly on marketing claims of enhanced performance and accelerated recovery from musculoskeletal injury, and that these peptides are often perceived as low risk despite the absence of efficacy or safety data [11]. Both are review articles; neither reports a primary reconstitution method.

Detection of peptidic agents in blood matrices

An analytical workflow was reported for the detection of 54 prohibited peptidic and non-peptidic doping agents in dried and liquid blood matrices, describing a fast, streamlined, and harmonised procedure intended to replace more labour-intensive sample-preparation steps [12]. This is an analytical-chemistry paper; it is relevant to how small peptides are detected in biological samples, not to how they are prepared for laboratory use.

If you are reading this for personal health reasons

This material is sold for laboratory research only, and we do not provide dosing, reconstitution, or medical guidance for personal use. Anyone considering a compound for themselves should speak to a licensed clinician. Nothing on this page is a recommendation for human use.