← Library

TB-500 (Thymosin β4)

Peptide Index
Research Use
Also known as Thymosin Beta-4, TB4-frag
Interaction Warning1 flagged
Do not combine TB-500 (Thymosin β4) with the following:
  • Active malignancy

Function

Primary
Wound healing · Muscle/tendon repair
Secondary
Anti-fibrotic · Cardiac repair (research)
Mechanism
Sequesters G-actin → promotes cell migration; upregulates metalloproteinases for ECM remodeling; anti-apoptotic; anti-inflammatory via NF-κB inhibition.
Evidence
Pre-clinical / Observational
Research
Phase I/II cardiac fibrosis trials (RegeneRx)

Dosing

Range
2–5 mg 2×/week (loading); 2 mg/week (maintenance)
Frequency
2×/week loading → weekly maintenance
Route
Subcutaneous · Intramuscular

Administration & Technique

Subcutaneous (SubQ)
Default route for most research and therapeutic peptides — best absorption for reconstituted powder.
Device31G × 5/16" insulin syringe (U-100). 100 units = 1 mL.
TechniquePinch skin at abdomen (2" from navel), outer thigh, or love handle. Insert at 45–90°. Rotate sites daily to prevent lipohypertrophy. Alcohol-swab site, air-dry, inject slow, hold 5 sec.
Intramuscular (IM)
Used for depot formulations, some GH secretagogues (localized delivery), and clinical protocols requiring faster systemic uptake.
Device23–25G × 1–1.5" needle. 1–3 mL syringe.
TechniqueVentrogluteal, vastus lateralis, or deltoid. Insert 90°, aspirate (optional), inject slowly. Rotate sites weekly.

Injection & Application Sites

Front
Back
Subcutaneous (SubQ)
  • Abdomen — 2 in (5 cm) away from the navel, either side. Fastest, most consistent SubQ absorption.
  • Flank / love handle — Lateral fat pad above the hip. Good rotation site when the abdomen is tender.
  • Outer thigh — Upper outer quadrant, a hand-width below the hip. SubQ pinch at 45°.
Intramuscular (IM)
  • Ventrogluteal — Palm on greater trochanter, index to ASIS — inject in the V. Safest IM site.
  • Dorsogluteal (upper outer) — Upper outer quadrant of the buttock. Used for depot IM; alternate sides each cycle.
  • Upper arm / deltoid — Back of the upper arm for SubQ; 2 in below the shoulder bone for IM.
  • Anterior thigh (vastus lateralis) — Middle third of the outer front thigh. Preferred IM site for self-injection.

Diagram is a general illustration, not a medical instruction. Rotate sites every injection, keep 1 in (2.5 cm) between recent sites, and avoid scars, moles, bruises and the navel area.

Cycling

4–6 week loading then 4–6 weeks maintenance; cycle off ≥4 weeks.

Timing & Interactions

When to take
Loading phase: 2–2.5 mg twice weekly for 4–6 weeks, then maintenance every 2 weeks. Timing of day is not critical.
Do not combine with
  • ·Active malignancy — angiogenic concern
Complements
  • ·BPC-157 — classic recovery pairing
  • ·GH secretagogues for structural rehab

Storage & Reconstitution

Powder (Pre-Reconstitution)
Refrigerate 2–8°C up to 24 months; freeze –20°C for long-term.
After Reconstitution
Refrigerated up to 4 weeks with bacteriostatic water.
Full BAC water & reconstitution guide →

Reconstitution Calculator

Concentration
2.50 mg/mL
Volume per dose
0.100 mL
Insulin syringe
10.0 units (U-100)

1 mL = 100 units on a standard U-100 insulin syringe. Draw to the nearest 0.5 unit and confirm dosing with a clinician before injection.

Your Notes

Your Notes

Sign in to save personal notes on TB-500 (Thymosin β4) and sync them to Vial Lab.

Benefits

  • ·Reported faster recovery from injury
  • ·Anti-fibrotic effects
  • ·Generally well tolerated in trials

Risks

  • ·Fatigue
  • ·WADA-prohibited in sport
  • ·No long-term human safety data

Contraindications

  • ·Active malignancy (theoretical)
  • ·Competitive athletes under WADA
  • ·Pregnancy

Regulatory

Not FDA-approved; compounded/research use

Veterinary Use (Pets)

Common in equine and canine sports rehab for soft-tissue and cardiac recovery. Loading protocol then maintenance.

Dogs (Canine)
Dose2–5 mg / 30 kg dog weekly (loading) → every 2 wks (maintenance)
RouteSubQ or IM
UseLigament/tendon rehab, cardiomyopathy support (research).
Cats (Feline)
Dose0.5–1 mg per cat weekly
RouteSubQ
UseWound recovery, HCM adjunct (research).
Limited feline data; conservative dosing.
Horses (Equine)
Dose10–20 mg IM weekly loading × 4 wks, then every 2 wks
RouteIM (gluteal or pectoral)
UseTendon, ligament, suspensory injuries; back soreness.
Prohibited in racing (ARCI Class 2) and FEI competition.
Full veterinary reference →

Functional Groups

RecoveryLongevityBodybuilding & Performance

Cited Works

  1. Goldstein AL et al. Thymosin β4: Therapeutic potential. Expert Opin Biol Ther. 2012;12:37-51.source
View full reference repository →
Sign in to save favorites & stacks