How many units is each TB-500 amount?
At 10 mg + 2 mL (5 mg/mL) on a U-100 syringe:
Generated from the calculator's own functions. Rows are evenly spaced reference amounts, not suggested amounts. Amber readings don't fit a 100-unit barrel.
| Amount | mcg | Volume (mL) | Syringe units |
|---|---|---|---|
| 0.25 mg | 250 | 0.05 | 5 |
| 0.5 mg | 500 | 0.1 | 10 |
| 1 mg | 1,000 | 0.2 | 20 |
| 1.5 mg | 1,500 | 0.3 | 30 |
| 2 mg | 2,000 | 0.4 | 40 |
| 2.5 mg | 2,500 | 0.5 | 50 |
| 3 mg | 3,000 | 0.6 | 60 |
| 5 mg | 5,000 | 1 | 100 |
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How much water for each TB-500 vial size?
TB-500 is sold in 2 common sizes (5 mg, 10 mg). The same water volume gives a different concentration in each, so the same reading means a different amount. Each cell shows mcg per unit with mg/mL in brackets.
| Vial | 1 mL | 2 mL | 3 mL |
|---|---|---|---|
| 5 mg | 50 (5) | 25 (2.5) | 16.67 (1.67) |
| 10 mg | 100 (10) | 50 (5) | 33.33 (3.33) |
How much bacteriostatic water for a 5 mg TB-500 vial?
1 mL → 5 mg/mL, so 2 mg is 40 units. 2 mL → 2.5 mg/mL, so 2 mg is 80 units. 3 mL → 1.67 mg/mL, so 2 mg is 120 units. The whole vial holds 2 draws of 2 mg.
How much bacteriostatic water for a 10 mg TB-500 vial?
1 mL → 10 mg/mL, so 2 mg is 20 units. 2 mL → 5 mg/mL, so 2 mg is 40 units. 3 mL → 3.33 mg/mL, so 2 mg is 60 units. The whole vial holds 5 draws of 2 mg.
Worked example: 10 mg vial, 2 mL, 2 mg
- Concentration. 10 mg ÷ 2 mL = 5 mg/mL (5,000 mcg/mL).
- Volume. 2 mg ÷ 5 mg/mL = 0.4 mL.
- Units. 0.4 mL × 100 = 40 units on a U-100 syringe.
- Check. One unit holds 50 mcg; 40 × 50 mcg = 2,000 mcg = 2 mg, which matches. The vial holds 5 draws of this size.
TB-500: notes for the arithmetic
Products sold as "TB-500" are not consistent: some labels describe full-length thymosin beta-4 and some a short acetylated fragment (Ac-LKKTETQ). The arithmetic is the same either way because it works in mg, but compare like with like.
For the lab procedure itself (materials, aseptic technique, mixing without foaming) see how to reconstitute peptides. For what bacteriostatic water is and how long an opened vial is kept, see the bacteriostatic water guide and the storage guide.
Frequently asked questions
How many units is 2 mg of TB-500?
It depends on the water volume. 10 mg + 2 mL = 5 mg/mL, so 2 mg is 0.4 mL, or 40 units on a U-100 syringe. With 1 mL instead it would be 20 units.
How much bacteriostatic water for a 5 mg TB-500 vial?
There is no single correct volume. 1 mL gives 5 mg/mL (50 mcg per unit); 2 mL gives 2.5 mg/mL (25 mcg per unit); 3 mL gives 1.67 mg/mL (16.67 mcg per unit). Pick the volume that makes your reading easy to measure on the barrel you have.
How much bacteriostatic water for a 10 mg TB-500 vial?
There is no single correct volume. 1 mL gives 10 mg/mL (100 mcg per unit); 2 mL gives 5 mg/mL (50 mcg per unit); 3 mL gives 3.33 mg/mL (33.33 mcg per unit). Pick the volume that makes your reading easy to measure on the barrel you have.
How many mg of TB-500 is 10 units?
10 units on a U-100 syringe is 0.1 mL. At 5 mg/mL (10 mg in 2 mL) that is 0.5 mg (500 mcg). At a different concentration the answer is different.
Is this a TB-500 dosing calculator?
It is an arithmetic tool. It converts an amount you enter into a volume and a syringe reading; it does not suggest amounts, schedules or uses. Not approved by the FDA for any use. Sold as a research chemical only.
Sources
Links checked 2026-10-19.