Dosage evidence
TB-500 (thymosin beta-4 fragment) Dosage: Why There Is No Established Dose
Listed by its chemical identity — thymosin beta-4, fragment (LKKTETQ) — with the nomination withdrawn and no human exposure data identified.
Where TB-500 (thymosin beta-4 fragment) stands with the FDA
“FDA has not identified any human exposure data drug products containing Thymosin Beta-4, Fragment.”
There is no dose to report
No human dosing evidence exists to cite. TB-500 is also frequently conflated with full-length thymosin beta-4, which is a different molecule with a different evidence base.
We would rather tell you this than publish a number. Pages that rank for “tb-500 (thymosin beta-4 fragment) dosage” routinely state precise-looking figures with no citation attached to them. A number without a source is not more useful than an honest absence — it is less useful, because it looks like it came from somewhere.
Convert your prescribed dose to syringe units
If a clinician has prescribed TB-500 (thymosin beta-4 fragment) for you, the number that matters next is how far to draw the syringe — and that depends on how much bacteriostatic water went into the vial, not on the peptide itself.
This converts a dose your prescriber has already given you into a volume and a number of units on a U-100 insulin syringe. It does not suggest a dose, and it does not tell you whether a peptide is appropriate for you. Most research peptides have no FDA-approved dosing, so there is no “standard” number for us to fill in. Doses here are in micrograms (mcg) — confusing mcg with mg is a 1,000-fold error and the single most common way people get this wrong.
Enter the dose your prescriber gave you, in micrograms, to see the volume and syringe units.
Your 5 mg vial in 2 mL of bacteriostatic water is —.
Keep reading
References
- 1.US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks — category 2 of the interim policies, and the list of substances nominated but withdrawn. FDA Human Drug Compounding. 2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
This page reports what regulators and published sources say about TB-500 (thymosin beta-4 fragment). It is not medical advice, not a recommendation to use TB-500 (thymosin beta-4 fragment), and not a dosing instruction. Every source above was opened and read on the date recorded in our data; regulatory status changes, so check the primary source before relying on it.