Thymosin Alpha-1 Reconstitution Calculator (mg → units)
A 5 mg vial of Thymosin α-1 mixed with 2 mL of bacteriostatic water holds 2,500 mcg/mL, so a 1.6 mg dose is 0.64 mL — 64 units on a U-100 insulin syringe. Change the vial, water or dose below, or read the chart for other mixes.
Thymosin α-1 dilution chart: 1.6 mg in units
| Vial | + 1 mL water | + 2 mL water | + 3 mL water | Doses per vial |
|---|---|---|---|---|
| 1.6 mg | 100 U 1 mL · 1,600 mcg/mL | 200 U 2 mL · 800 mcg/mL over 1 mL — more than one syringe | 300 U 3 mL · 533 mcg/mL over 1 mL — more than one syringe | 1 |
| 5 mg | 32 U 0.32 mL · 5,000 mcg/mL | 64 U 0.64 mL · 2,500 mcg/mL | 96 U 0.96 mL · 1,667 mcg/mL | 3.1 |
| 10 mg | 16 U 0.16 mL · 10,000 mcg/mL | 32 U 0.32 mL · 5,000 mcg/mL | 48 U 0.48 mL · 3,333 mcg/mL | 6.3 |
1 mL = 100 units on a U-100 syringe. Water volume changes the units per dose, never the number of doses in the vial.
Measuring Thymosin α-1: the math that matters
Thymosin alpha-1 has a reference point most research peptides lack: Zadaxin, the prescription product approved in a number of countries outside the US, is a 1.6 mg vial reconstituted with 1.0 mL of its supplied diluent immediately before use. That makes 1,600 mcg/mL, and the whole vial, 100 units on a U-100 syringe, is one 1.6 mg dose. A 5 mg research vial with 2 mL is 2,500 mcg/mL, where 1.6 mg is 0.64 mL, or 64 units.
The 1.6 mg single-dose vial leaves no margin. Adding 2 mL instead of 1 mL doubles the volume to 200 units, two full syringes, for the same amount of peptide. And drawing a vial completely always leaves a little liquid in the vial and needle, so the delivered amount from a single-dose vial is slightly under the label figure.
Multi-dose research vials change the numbers. A 5 mg vial holds about three 1.6 mg doses (3.1), and a 10 mg vial holds six (6.2), in both cases with a remainder smaller than a full dose. With a 10 mg vial and 2 mL, 1.6 mg is 32 units; with 1 mL it is 16 units, which lands on a 2-unit line and is easy to read.
The Zadaxin label expresses the dose two other ways, and both can mislead a calculator. 1.6 mg corresponds to 900 mcg per square metre of body surface, the figure for a body surface area of about 1.8 m². For people under 40 kg the label uses 40 mcg per kg instead, which for a 30 kg person is 1.2 mg. Enter the final amount in mg or mcg, never the per-m² or per-kg figure.
Common Thymosin α-1 measuring mistakes
- Entering 900 (the mcg/m² figure) as the dose in mcg.
- Mixing a 1.6 mg single-dose vial with more than 1 mL and needing more than one syringe for the dose.
- Expecting a whole number of doses from a 5 mg or 10 mg vial. Both leave a partial dose.
- Confusing thymosin alpha-1 with thymosin beta-4 or TB-500, which are different molecules with different amounts.
- Keeping units from a 10 mg vial when switching to a 5 mg vial at the same water volume.