TB-500 (thymosin beta-4): doses reported in published research

Sources checked 2026-10-07 · 7 cited studies (4 human, 3 animal, 0 cell culture)

The studies below used thymosin beta-4 (Tβ4), a 43-amino-acid protein, either synthetic or recombinant. Products sold as "TB-500" are labelled as Tβ4 or a Tβ4 fragment; the published doses refer to the molecule named in each study.

Human data: two phase 1 intravenous studies in healthy volunteers and phase 2 eye-drop studies (0.1% solution) in dry eye.

Studies in people (4)

Human Healthy volunteers, phase 1, randomized and placebo-controlled (four cohorts of 10)

Dose as reported: 42, 140, 420 or 1260 mg (synthetic Tβ4)
Route: Intravenous
Frequency / duration: Single dose, then the same dose daily for 14 days

Source wording: Four cohorts, with 10 healthy subjects each, were given a single intravenous dose of placebo or synthetic Tbeta4. Cohorts received ascending doses of either 42, 140, 420, or 1260 mg. subjects were given the same dose regimen daily for 14 days

Ruff D, Crockford D, Girardi G et al.. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci 2010. PubMed PMID 20536472 ↗

Human Healthy Chinese volunteers, phase 1, randomized and double-blind (54 single-dose, 30 multiple-dose)

Dose as reported: Single: 0.05, 0.25, 0.5, 2.0, 5.0, 12.5 or 25.0 µg/kg. Multiple: 0.5, 2.0 or 5.0 µg/kg (recombinant Tβ4, NL005)
Route: Intravenous
Frequency / duration: Single dose; or once daily for 10 days

Source wording: The cohorts received ascending doses of either 0.05, 0.25, 0.5, 2.0, 5.0, 12.5 or 25.0 μg/kg in the single-dose trial. 3 cohorts (0.5, 2.0 and 5.0 μg/kg) were administered once human thymosin β4 daily for 10 days recombinant human thymosin β4 (NL005)

Wang X, Liu L, Qi L et al.. A first-in-human, randomized, double-blind, single- and multiple-dose, phase I study of recombinant human thymosin β4 in healthy Chinese volunteers. J Cell Mol Med 2021. PubMed PMID 34346165 ↗

Human Nine people with severe dry eye, phase 2, vehicle-controlled

Dose as reported: 0.1% ophthalmic solution (RGN-259)
Route: Eye drops
Frequency / duration: 6 times daily for 28 days

Source wording: Nine patients with severe dry eye were treated with either RGN-259 (0.1%) or vehicle control 6 times daily over a period of 28 days.

Sosne G, Dunn SP, Kim C. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea 2015. PubMed PMID 25826322 ↗

Human 72 people with dry eye, phase 2, placebo-controlled

Dose as reported: 0.1% ophthalmic solution
Route: Eye drops
Frequency / duration: 28 days (frequency not stated in the abstract)

Source wording: randomized 72 qualifying subjects 1:1 to receive either 0.1% Tβ4 or placebo treatment for a total of 28 days.

Sosne G, Ousler GW. Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial conducted using the controlled adverse environment (CAE™) model. Clin Ophthalmol 2015. PubMed PMID 26056426 ↗

Animal studies (3)

Animal doses are listed exactly as the studies report them. They are not converted to human amounts here; doses do not translate between species by body weight.

Animal Rats (embolic stroke model), 10 per group

Dose as reported: 2, 12 or 18 mg/kg (separate groups)
Route: Intraperitoneal
Frequency / duration: 24 h after stroke induction, then every 3 days for 4 more doses

Source wording: Rats were divided into 4 groups of 10 animals/group: control, 2, 12 and 18 mg/kg. Tβ4 was administered intraperitoneally 24h after MCAo and then every 3 days for 4 additional doses

Morris DC, Cui Y, Cheung WL et al.. A dose-response study of thymosin β4 for the treatment of acute stroke. J Neurol Sci 2014. PubMed PMID 25060418 ↗

Animal Rats (traumatic brain injury model)

Dose as reported: 6 mg/kg
Route: Intraperitoneal
Frequency / duration: From day 1, then every 3 days for 4 more doses

Source wording: Thymosin β(4) (6 mg/kg) or saline was administered intraperitoneally starting at Day 1 and then every 3 days for an additional 4 doses.

Xiong Y, Mahmood A, Meng Y et al.. Treatment of traumatic brain injury with thymosin β₄ in rats. J Neurosurg 2011. PubMed PMID 20486893 ↗

Animal Mice (bilateral fibular osteotomy)

Dose as reported: 6 mg/kg
Route: Intraperitoneal
Frequency / duration: Not stated in the abstract

Source wording: injections of either Tβ4 (6 mg/kg) or saline.

Brady RD, Grills BL, Schuijers JA et al.. Thymosin β4 administration enhances fracture healing in mice. J Orthop Res 2014. PubMed PMID 25042765 ↗

Half-life

Human Half-life increased with dose after single intravenous doses of 42-1260 mg in healthy volunteers (no single value given in the abstract). Source wording: Pharmacokinetic profile for single dose showed a dose proportional response, and an increasing half-life with increasing dose. over a dose range of 42-1260 mg
Ruff D, Crockford D, Girardi G et al.. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci 2010. PubMed PMID 20536472 ↗

About this page

Every figure above is copied from the cited source; the source wording is shown with each entry. Where a source does not state something, the page says so.
Only abstracts, open-access full texts, registry records and FDA labels were used, so details found only in a paywalled full text may be missing.
This page does not convert doses between species or into other measures, and gives no preparation or handling information.