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Peptides · Tissue repair (under FDA review)
TB-500 / Thymosin Beta-4
Thymosin beta-4 fragment under FDA review.
What it does
What TB-500 / Thymosin Beta-4 is and why doctors prescribe it.
TB-500 is a synthetic peptide based on a naturally occurring region of thymosin beta-4, an actin-binding protein abundant in human cells. Research interest focuses on tissue repair, wound healing, and inflammation modulation. Currently in Category 2, under FDA review for potential movement to 503A access.
How it works
Mechanism in plain English.
Thymosin beta-4 binds G-actin monomers, regulating actin polymerization and cell migration. In wound healing and tissue repair, this affects keratinocyte and endothelial cell migration, angiogenesis, and reduction of inflammatory cytokines. Synthetic TB-500 is designed to capture the active fragment.
How long it's been studied
Research history.
Thymosin beta-4 has been studied since the 1980s; the TB-500 peptide fragment has been the subject of clinical trials in dry-eye disease, wound healing, and venous stasis ulcers, with mixed but generally suggestive results. Cannot currently be compounded under 503A.
Dosing
Clinical context for the prescribing doctor.
Pending regulatory clarity. RonanRx cannot compound TB-500 until it receives 503A-permissible status. Once permitted, dosing will be doctor-prescribed based on indication and available evidence.
This page is informational, not a dispensing aid. TB-500 / Thymosin Beta-4 is dispensed only on a patient-specific prescription written by a licensed doctor for an identified patient. Compounded drugs are not FDA-approved and should not be evaluated using branded-drug trial data. Availability varies by state and prescribed medication.
How to access TB-500 / Thymosin Beta-4 through RonanRx
Three paths.
TB-500 / Thymosin Beta-4 is currently in Category 2 and not available for 503A compounding. RonanRx is tracking the FDA review and will notify partner clinics when the decision allows compounding access.
Patient with a doctor
Sign up to receive your prescription.
If your doctor has already prescribed TB-500 / Thymosin Beta-4, sign up so we can prepare and ship your medication. The signup wizard collects intake and connects you to the prescribing workflow.
Patient without a doctor
Get referred by a partner clinic.
RonanRx prescribes through partner clinics — we don't initiate prescriptions on this site. Read how the referral process works and how to find a partner clinic in your state.