Skip to content

Repair

All peptides
Thymosin Beta-4 fragment

TB-500

Also known as: Thymosin Beta-4 fragment, TB4 fragment, Thymosin Beta-4, TB-4

Animal-data peptide marketed as a tissue-repair adjunct. No published human RCTs for musculoskeletal indications.

Reviewed 2026-04-30

What it does

TB-500 is a synthetic peptide marketed as a fragment of thymosin beta-4 (Tβ4), a 43-amino-acid actin-sequestering protein with documented roles in tissue repair, angiogenesis, and inflammation modulation in animal models. Confusingly, the term 'TB-500' is sometimes used for the full Tβ4 molecule and sometimes for a 7-amino-acid fragment containing the actin-binding region. Full Tβ4 has been investigated in early-stage human trials for wounds, dry eye, and post-MI cardiac repair, sponsored by RegeneRx; outcome data is mixed and trials are small. The 'TB-500' fragment marketed in self-experimenter channels has no published human RCTs.

Used for

Dose

Starting
2,000 mcg · twice weekly (loading) → weekly (maintenance)
Common
3,500 mcg · twice weekly (loading) → weekly (maintenance)
Upper
5,000 mcg · twice weekly (loading) → weekly (maintenance)
When
FlexibleTwice-weekly typical; long half-life makes time-of-day non-load-bearing. Most community protocols pick a consistent dosing day + time for tracking.
How long
2 months on / 1 month off
Site
subcutaneous
Food
any

Need exact volumes? Open the peptide calculator →

⚠ Caution

  • Active malignancy (Tβ4 promotes angiogenesis and cell migration in animal models)
  • Pregnancy and breastfeeding
  • Active competitive athletes — Tβ4 is on the WADA prohibited list
  • Hypersensitivity to peptide formulations

Will it work for me?

Establish a baseline (2–3 readings over 1–2 weeks before starting), then track at consistent intervals.

Blood markers
  • Tier 2 — Human observationalhs-CRP / ESR↓· 6–12 weeksInflammation overlay, not a direct action marker.
Functional & psychometric
  • Tier 3 — Animal / in vitroRegion-specific function score (DASH / KOOS / ODI) + ROM↑· 6–12 weeksSelf-administered functional tracking is the practical default.
  • Tier 3 — Animal / in vitroPain scale (VAS / NPRS)↓· 2–4 weeks

Often stacked with

  • BPC-157 — BPC-157 promotes angiogenesis at injury sites; TB-500 (Tβ4 fragment) enhances actin-driven cell migration — parallel tissue-repair pathways that do not duplicate each other.
  • GHK-Cu — GHK-Cu promotes ECM remodeling and angiogenic gene expression; TB-500 mobilizes stem cells and drives actin-dependent cell migration — complementary phases of wound-healing cascade.
  • KPV — KPV blunts NF-κB-driven inflammation at the tissue level; TB-500 accelerates cell migration and tissue remodeling — sequential anti-inflammatory + repair targeting.

Your stack

Track this peptide in your protocol — dose, schedule, vials on hand, refill projection. Stays in your browser; no account needed.

Add to my stack

Use this peptide

Featured in protocols
Cycling

2 months on, 1 month off.

Related peptides

Part of these blends

Co-injection & overlap

Can share a syringe with: BPC-157, GHK-Cu, KPV

Reconstitution & storage
VialBAC waterConcentrationShelf life
10 mg1 mL2 mg per 20 units2 weeks

Some protocols front-load with daily dosing for the first 1–2 weeks, then taper to twice-weekly maintenance. Dose volume can be significant at multi-mg doses — split between two injection sites if a single draw is uncomfortable.

Storage. Lyophilized: refrigerate 2–8 °C. Reconstituted: refrigerate 2–8 °C, use within 30 days. Avoid agitation.

Open the peptide calculator →

Nasal delivery

Not suitable for nasal delivery. SQ only when targeting systemic/tissue effect — molecular size and the need for systemic distribution preclude reliable nasal absorption.

Monitoring & questions

Reported side effects
  • Injection site reactions
  • Headache
  • Mild fatigue
  • Theoretical concern: angiogenesis-promoting activity is not benign in the wrong context
  • No long-term human safety data — flag explicitly
Biomarkers Juno tracks
FAQ (1)

Reference

How it works

Tβ4 binds and sequesters G-actin, modulating cell migration, angiogenesis, and stem-cell mobilization. The Tβ4 17-23 fragment retains the actin-binding region but lacks the full-length protein's other functional domains. Whether the fragment recapitulates Tβ4's clinical effects is not directly tested in humans.

EvidenceTier 3 — Animal / in vitro

Tiers are per indication. The same molecule can be Tier 1 for one use and Tier 4 for another — the tier reflects published literature, not community framing.

Tissue / tendon repair

Tier 3high confidence

Animal models of tendon, ligament, and skin wound healing show consistent effects with full-length Tβ4 and (in fewer studies) the 17-23 fragment. No published human RCTs evaluate the fragment for musculoskeletal repair.

Goldstein AL et al. 2012

Cardiac repair after myocardial infarction

Tier 2low confidence

Early-phase human studies of full-length Tβ4 in post-MI populations have produced mixed results; trials are small and the fragment is not what was studied.

Goldstein AL et al. 2012

Athletic performance / recovery

Tier 4high confidence

No published primary literature evaluating the fragment for athletic recovery endpoints. Anti-doping agencies (WADA) prohibit Tβ4 in competitive sport regardless of evidence.

No primary citations are anchored to this indication — the tier reflects the absence of usable literature, not a missing reference.

Citations (1)
  1. [1]
    Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications
    Goldstein AL, Hannappel E, Sosne G, Kleinman HK · Expert Opinion on Biological Therapy · 2012 · PMID 23173600
    Comprehensive review of Tβ4 mechanisms and human pilot trials.
    View source