August 29, 2026
RESEARCH USE ONLY. This page contains unit-conversion arithmetic only. It is not a dosing guide, not a protocol, and not a preparation or administration instruction for any person or animal. Products discussed on this site are supplied strictly for laboratory and research purposes.
TB-500 is sold in three vial sizes. One point worth knowing before the arithmetic: the material sold as TB-500 is the Ac-LKKTETQ fragment, not full-length thymosin beta-4, and much of the published literature used the full-length protein. That does not change the maths below, but it changes what the literature is evidence for — and most vendor pages blur the two.
| Bacteriostatic water added | Concentration | Contained in 10 units | Contained in 20 units |
|---|---|---|---|
| 1 mL | 10 mg/mL | 1 mg | 2 mg |
| 2 mL | 5 mg/mL | 0.5 mg | 1 mg |
| 3 mL | 3.33 mg/mL | 0.333 mg | 0.667 mg |
| 5 mL | 2 mg/mL | 0.2 mg | 0.4 mg |
| Bacteriostatic water added | Concentration | Contained in 10 units | Contained in 20 units |
|---|---|---|---|
| 1 mL | 5 mg/mL | 0.5 mg | 1 mg |
| 2 mL | 2.5 mg/mL | 0.25 mg | 0.5 mg |
| 3 mL | 1.67 mg/mL | 0.167 mg | 0.333 mg |
| 5 mL | 1 mg/mL | 0.1 mg | 0.2 mg |
| Bacteriostatic water added | Concentration | Contained in 10 units | Contained in 20 units |
|---|---|---|---|
| 1 mL | 2 mg/mL | 0.2 mg | 0.4 mg |
| 2 mL | 1 mg/mL | 0.1 mg | 0.2 mg |
| 3 mL | 0.67 mg/mL | 0.067 mg | 0.133 mg |
| 5 mL | 0.4 mg/mL | 0.04 mg | 0.08 mg |
Worked example: a 5 mg vial reconstituted with 2 mL gives 2.5 mg/mL. Twenty units is 0.2 mL. 0.2 mL × 2.5 mg/mL = 0.5 mg.
An insulin syringe is graduated in units, which are a volume marking, not a mass. On both U-100 and U-50 insulin syringes, one unit corresponds to 0.01 mL. The difference is barrel capacity and gradation spacing — not the unit-to-volume relationship. A U-50 holds 0.5 mL across 50 units; a U-100 holds 1.0 mL across 100 units. Both are 100 units per millilitre.
The arithmetic is: mass = (peptide mg ÷ mL of solvent added) × (units × 0.01)
Our reconstitution calculator runs this across a 44-compound library if you would rather not do it by hand.
Sourced fact: The Bacteriostatic Water for Injection label directs: “Do not store reconstituted solutions of drugs for injection unless otherwise directed by the manufacturer of the solute.” [1]
Inference: The widely-quoted 28-day figure describes the multiple-dose container of water, not what you dissolved in it. We traced that rule to its actual source in where the 28-day rule actually comes from — it is not printed on the FDA label at all.
This is unit-conversion arithmetic for laboratory research planning. It is not medical or veterinary advice, not a protocol, not a recommendation of any volume, and not an instruction to administer anything to any person or animal. TB-500 is not approved by the FDA for human or veterinary use.
Reconstitution arithmetic for every compound in the catalogue: BPC-157 · TB-500 · Wolverine Stack · GLOW · KLOW · CJC-1295 / Ipamorelin · Ipamorelin · CJC-1295 No DAC · GHK-Cu · Epitalon · MOTS-c · AOD-9604 · NAD+ · PT-141 · Tesamorelin · Retatrutide · Tirzepatide · SS-31 · Selank · Semax · KPV · DSIP · PEG-MGF · FOXO4-DRI · ARA-290 · 5-Amino-1MQ
TB-500 · Bacteriostatic Water, USP · Reconstitution calculator · Reconstitution handling guide · Wolverine Stack arithmetic · BPC-157 arithmetic
RESEARCH USE ONLY — FULL DISCLAIMER. The products discussed on this page are supplied strictly for laboratory and scientific research purposes. They are not for human or veterinary use, and not for consumption. These statements have not been evaluated by the Food and Drug Administration. Nothing on this page is intended to diagnose, treat, cure, or prevent any disease in humans or animals. Nothing here constitutes medical or veterinary advice or a dosing, preparation, or administration recommendation for any person or animal.
