Thymosin Beta 4
TB-4 / Tβ4 / Full-length TB-4
The full 43-amino-acid parent peptide from which TB-500 is derived. Thymosin Beta 4 is a naturally occurring actin-sequestering protein involved in tissue repair, cell migration, anti-inflammation, and angiogenesis. The full-length form provides additional bioactive fragments beyond what TB-500 (Ac-SDKP region) alone offers.
Half-life
~2 hours (rapidly processed to active fragments)
Typical Dose
750 mcg – 2 mg/day
Route
subcutaneous
Category
healing
Evidence Overview
Strength of evidence across clinical, expert, and experimental lanes.
How Thymosin Beta 4 is dosed in practice
Usually taken by subcutaneous (SubQ) injection. Typical range: 750 mcg – 2 mg/day. Half-life: ~2 hours (rapidly processed to active fragments). Each card gives the dose, frequency and duration from one evidence lane: Clinical (human trials), Expert (practitioner protocols) or Experimental (early or animal data). These ranges describe what has been studied or used; they are not a prescription.
Work out the units to draw with the reconstitution calculator, how long a vial lasts with the vial duration calculator, and how levels fall between doses with the half-life calculator.
Human trials used eye drops (0.1%) for dry eye and corneal defects, a topical gel for venous ulcers, and IV doses for 14 days in a healthy-volunteer safety study, which were well tolerated. Dry-eye results were mixed (one trial missed its primary endpoints), and no cardiac efficacy results have been published. No human study of SubQ dosing has been published.
- IV safety study in healthy volunteers (2010)
- Topical gel trial in venous ulcers (2010)
- Eye-drop trials in dry eye and corneal defects (2015)
Practitioners prefer full-length TB-4 over TB-500 for systemic healing as it provides all bioactive regions. Used for cardiac recovery, neurological injury, and complex wound healing. Often stacked with BPC-157 at a 1:4 ratio.
- Regenerative medicine practitioners — systemic healing protocols
- Clinical Peptide Protocols — Practitioner Guidelines
- Integrative cardiology case reports
Users report faster recovery from injuries and surgeries compared to TB-500 alone. Some report improvements in hair regrowth and cardiac function markers. Higher cost than TB-500 limits widespread adoption.
- Reddit r/Peptides — comparative reports TB-4 vs TB-500
- Biohacking community wound healing logs
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Upgrade to ProSafety & Contraindications
- Active cancer or history of cancer (promotes angiogenesis and cell migration)
- Pregnancy or breastfeeding
- Active infection requiring immune surveillance
Thymosin Beta 4: common questions
What is Thymosin Beta 4?
The full 43-amino-acid parent peptide from which TB-500 is derived. Thymosin Beta 4 is a naturally occurring actin-sequestering protein involved in tissue repair, cell migration, anti-inflammation, and angiogenesis. The full-length form provides additional bioactive fragments beyond what TB-500 (Ac-SDKP region) alone offers.
How is Thymosin Beta 4 dosed?
Thymosin Beta 4 is usually taken by subcutaneous (SubQ) injection. Typical range in DoseCraft's library: 750 mcg – 2 mg/day. Clinical (human trials): 0.1% eye drops; topical gel on venous ulcers; 42–1260 mg/day IV in a safety study; Eye drops several times daily; IV once daily; 14–84 days. Expert (practitioner protocols): 750 mcg – 2 mg/day; Once daily or split AM/PM; 6–8 week cycles. Experimental (early or animal data): 1–2 mg/day; Once daily; 8–12 weeks. These ranges describe what has been studied or used; they are not a prescription.
Is Thymosin Beta 4 FDA-approved?
No. Thymosin Beta 4 is not approved by the FDA for any use in people.
What is the half-life of Thymosin Beta 4?
DoseCraft's library lists a half-life of ~2 hours (rapidly processed to active fragments). Half-life sets how often a compound is dosed and how long it takes to clear: about five half-lives.
Who should not use Thymosin Beta 4?
Listed contraindications: Active cancer or history of cancer (promotes angiogenesis and cell migration); Pregnancy or breastfeeding; Active infection requiring immune surveillance.
Free Guides for Thymosin Beta 4
Information is for educational purposes only. Always consult a licensed healthcare provider before starting any peptide regimen.
Page updated . How we grade evidence: methodology.