TB-500

Mechanism

Actin-sequestering signal associated with cell migration and angiogenesis.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

• Soft-tissue repair
• Post-surgical recovery
• Anti-inflammatory support

Reconstitution

mass ÷ diluent = concentration; dose ÷ concentration = volume; volume × the syringe factor = units on the barrel (100 for U-100, 40 for U-40). Run your own numbers.

Half-life, storage & sport

Elimination half-life

0.5-2.08 hours (dose-dependent) (human, IV) — study. recombinant human thymosin beta-4 (NL005) first-in-human phase I, 0.05-25 ug/kg.

Storage

Lyophilised: Stable at room temperature ~3 weeks; store desiccated below -18C for long term. Reconstituted: 4C for 2-7 days; below -18C for future use; avoid freeze-thaw; carrier protein recommended for long-term. — source. ProSpec synthetic thymosin beta-4 technical datasheet. Supplier handling recommendation for research-grade lyophilate, not a per-compound stability study.

In sport (WADA 2026)

Prohibited, at all times — named S2.3 (growth factors: thymosin-beta4 and its derivatives, e.g. TB-500). the list

The half-life on file is 1.3 h, measured intravenously. On the schedule this record states — twice a week — each dose has fallen to under 0.1% of its own peak by the time the next is given. Nothing accumulates, and there is no loading phase to run.

The half-life was measured by a route this is not given by. That makes it a lower bound rather than an estimate: absorption from an injection site goes on supplying the blood after an intravenous bolus would have cleared, so the real curve is flatter and lasts longer than the one drawn here. It is never shorter.

The rise is not modelled and the axis is not a blood level. No absorption rate constant and no volume of distribution are on file, so each dose appears at full height the instant it is given, and the axis is percent of this compound's own peak.

Reported adverse effects

No controlled human safety data exists.

• Lethargy after initial doses

  Anecdotally reportedonset: First dosesreported reversible

Literature on file 7

• animal in vivo
  Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair (Nature 2004, cited 576x) graded on: an animal model — read from the indexed abstract — “mice”
• animal in vivo
  Thymosin β4 induces adult epicardial progenitor mobilization and neovascularization (Nature 2006, cited 572x) graded on: an animal model — read from the indexed abstract — “mice”
• review or editorial
  Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians. graded on: indexed as "Review" - secondary literature, not a study — “Review”
• review or editorial
  Therapeutic peptides in gerontology: mechanisms and applications for healthy aging. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
• review or editorial
  Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. graded on: indexed as "Review" - secondary literature, not a study — “Review”
• animal in vivo
  Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study. graded on: an animal model — “rats”

Not graded

1 citation whose study design could not be read from the title. Left ungraded rather than guessed at.

• not graded
  NCT07487363: A Phase 1/2, Randomized, Double-Blind, Placebo-Controlled, Sequential Dose-Escalation Study of TB-500 (Thymosin Beta 4 17-23 Fragment) in Adults With Stable Atherosclerotic Cardiovascular Disease to Evaluate Safety, Tolerability, Pharmacokinetics, and Exploratory Cardiovascular Biomarkers graded on: NCT07487363 is recruiting and has posted no results - a registration, not a reported outcome — “NCT07487363”

What is circulated not evidence 6

Claims passed around in community guides and vendor copy, recorded because they circulate — not because they are true. Each is shown with the page it was read from and what this record actually holds. Checked 2026-08-24.

• unverified community data titration ubiquitous nothing on file either way

  A two-phase protocol is near-universal in community and vendor guides: a loading phase of roughly 4 to 7.5 mg per week split over two injections for four to six weeks, dropping to 2.5 to 4 mg per week as maintenance.

  4 to 7.5 mg total per week for 4 to 6 weeks, divided into two injections

  On the record The record holds a single flat range, 2-4 mg per administration twice weekly on a cycle of 4-8 weeks, and marks it unverified. There is no loading phase, no maintenance phase and no weekly total on file at all.

  Source 1 · Source 2

• unverified community data timing common nothing on file either way

  Twice-weekly injection is justified in guides by the peptide's half-life, with daily injection said to add nothing.

  Twice-weekly administration aligns with this half-life. More frequent daily injection offers no clear advantage.

  On the record The record holds a half-life of 0.5-2.08 hours, dose-dependent, for TB-500; the thymosin beta-4 record gives 0.95 to 2.1 h across 42 mg to 1260 mg. Nothing on file connects that half-life to a dosing interval, and a half-life of two hours does not itself support a three-day gap.

  Source 1

• unverified community data storage common contradicts the record

  Reconstituted TB-500 is stated to keep for up to 28 days refrigerated.

  Refrigerated at 2 to 8°C, the reconstituted solution keeps for up to 28 days.

  On the record The record holds '4C for 2-7 days; below -18C for future use; avoid freeze-thaw; carrier protein recommended for long-term'. The circulated figure is four times the upper bound on file.

  Source 1

• unverified community data side effect common nothing on file either way

  Mild fatigue or local warmth around days three to five is described as an expected and unremarkable part of a course, and persistent headache as the signal to stop.

  Days 3 to 5: mild fatigue or localized warmth may occur and are generally unremarkable.

  On the record The record holds 'No controlled human safety data exists' and 'Lethargy after initial doses'. The lethargy matches; the day-3-to-5 timing, the local warmth and the headache stopping rule are not on file, and nothing on file supports calling any of it unremarkable.

  Source 1

• unverified community data titration common contradicts the record

  Cycles of eight weeks for acute injury out to sixteen weeks or more for performance, with four to eight weeks off between, are the ranges stated in guides.

  4 to 7.5 mg total per week for 4 to 6 weeks, divided into two injections

  On the record The record holds a cycle of 4 to 8 weeks. The circulated upper bound of sixteen weeks or more is double the maximum on file, and no washout interval is on file.

  Source 1

• unverified community data sourcing occasional agrees with the record

  At least one dosing guide states plainly that the human pharmacokinetic and safety data belong to intravenous thymosin beta-4 rather than to the subcutaneous fragment actually sold as TB-500.

  Controlled human pharmacokinetic and safety data exist only for intravenous thymosin beta-4 in healthy volunteers, not for the subcutaneous synthetic peptide sold for research.

  On the record The record keeps TB-500 and thymosin beta-4 as separate entries and grades them differently: TB-500 on animal evidence, with its human registration NCT07487363 still recruiting, while thymosin beta-4 rests on a human randomised controlled trial. That the circulated dosing borrows the parent molecule's human data is consistent with the split on file but is not itself stated anywhere in the record.

  Source 1

Identity

PubChem CID 62707662 computed 3D conformer

Skeletal formulathe canonical depiction

Drawn by PubChem from CID 62707662, the identifier on this record.

Molecular weight

4963.4408

Molecular formula

C38H68N10O14

CAS number

885340-08-9

PubChem CID

62707662

InChI key

ADKDNDYYIZUVCZ-ZQNQAVPYSA-N

Sequence

LKKTETQ

SMILES

C[C@H]([C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CCC(=O)N)C(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(C)C)NC(=O)C)O

InChI

InChI=1S/C38H68N10O14/c1-19(2)18-27(42-22(5)51)35(58)44-23(10-6-8-16-39)32(55)43-24(11-7-9-17-40)33(56)47-30(20(3)49)36(59)45-25(13-15-29(53)54)34(57)48-31(21(4)50)37(60)46-26(38(61)62)12-14-28(41)52/h19-21,23-27,30-31,49-50H,6-18,39-40H2,1-5H3,(H2,41,52)(H,42,51)(H,43,55)(H,44,58)(H,45,59)(H,46,60)(H,47,56)(H,48,57)(H,53,54)(H,61,62)/t20-,21-,23+,24+,25+,26+,27+,30+,31+/m1/s1

Classified as

Angiogenesis Modulationmechanism

New vessel growth is one of the concrete, measurable steps in the Wound Healing Cascade, so this is where a repair claim can be traced to something specific rather than left as the word healing.

Subcutaneousroute

This is the route the reconstitution arithmetic assumes. Mass divided by diluent volume gives concentration, dose divided by concentration gives volume, and volume in mL multiplied by 100 gives units on a U-100 barrel: 5 mg in 2 mL is 2.5 mg/mL, and 0.25 mg comes out at 0.1 mL, which is 10 units.

Also called

• TB-500
• TB-500 (Thymosin Beta-4 frag)
• TB-500 (Thymosin Beta-4 fragment)
• tb 500 thymosin beta 4

Listed prices 336

What 190 shops we track listed for TB-500, read from their own public catalogues on 2026-09-14. We take no commission on these and they are not ranked by any payment — how vendors are scored.

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