TB-500 reconstitution calculator
Opens on a 10 mg vial, 2.5 mL of bacteriostatic water and a 300 mcg dose, amounts recorded for TB-500 in the compound library. Change any field and the draw updates.
Also known as Thymosin Beta-4.
Original calculator
The classic all-in-one form
Every input on one card, the way the original site worked.
Typical vial strength and dose filled in; recorded examples appear as one-tap presets.
- Draw 8 units for 300 mcg doses of TB-500.
- Concentration 4 mg/mL (10 mg in 2.5 mL). Each vial holds 33 doses of 0.07 mL.
The exact draw is 7.5 units; the syringe reads in whole units. 8 units deliver about 320 mcg, 20 mcg over the amount entered.
For research and educational use. This calculator does not provide medical advice.
How the numbers work for TB-500
A 10 mg vial of TB-500 with 2.5 mL of bacteriostatic water is 10 / 2.5 = 4 mg/mL. A 300 mcg dose (0.3 mg) is 0.3 / 4 = 0.075 mL, which is 8 units on a U-100 syringe, or the same number of clicks on a pen. With 3 mL of water instead, the concentration is 3.33 mg/mL and the same dose is 9 units. At that dose the vial holds 33 doses.
The formulas are the same for every compound: concentration is the vial amount divided by the water, the draw is the dose divided by the concentration, and a U-100 unit is 0.01 mL. They are written out on the methodology page.
TB-500 units at a glance
Syringe units for the amounts recorded for TB-500, from a 10 mg vial, across the water volumes people most often use. These are recorded examples used for the arithmetic, not recommendations; a draw under 6 units is hard to measure repeatably and more water fixes that.
| Dose | 1 mL water10 mg/mL | 2 mL water5 mg/mL | 3 mL water3.33 mg/mL |
|---|---|---|---|
| 300 mcg | 3 units0.03 mL | 6 units0.06 mL | 9 units0.09 mL |
| 1 mg | 10 units0.1 mL | 20 units0.2 mL | 30 units0.3 mL |
| 2 mg | 20 units0.2 mL | 40 units0.4 mL | 60 units0.6 mL |
| 3 mg | 30 units0.3 mL | 60 units0.6 mL | 90 units0.9 mL |
Where the amounts come from
The doses above are recorded amounts from the TB-500 entry in the compound library, which lists the sources behind them, labels each as clinical, preclinical or community-reported, and states what the evidence can and cannot support. The vial strength is the one most often listed by suppliers. Nothing on this page is medical advice.
Common questions about TB-500
- Is TB-500 an FDA-approved medicine?
- TB-500 (thymosin beta-4 fragment) is not an approved medicine anywhere. FDA reviewed it as a bulk substance for compounding, placed it in category 2 for immunogenicity and impurity concerns, and the nomination was later withdrawn, so it is on no list of substances that may be compounded. In July 2026 FDA's Pharmacy Compounding Advisory Committee voted, against FDA staff's recommendation, to recommend it for the 503A bulks list; the vote is advisory and no rule has been proposed, so its status is unchanged.
- How much bacteriostatic water do I add to a 10 mg vial of TB-500?
- There is no single right amount: the water sets the concentration and the size of the draw, not the dose. This page opens on 2.5 mL, which makes 4 mg/mL and puts a 300 mcg dose at 8 units on a U-100 syringe. With 1 mL the same dose is 3 units; with 3 mL it is 9 units. More water gives a larger, easier-to-read draw, as long as the vial can hold it.
- How many units is 300 mcg of TB-500?
- At 4 mg/mL (10 mg in 2.5 mL of water), 300 mcg is 0.075 mL, which is 8 units on a U-100 insulin syringe or 8 clicks on a peptide pen. At any other concentration the number changes; the units table on this page gives the other common water volumes.
- How many doses are in a 10 mg vial of TB-500?
- At 300 mcg per dose, a 10 mg vial holds 33 doses. The water volume changes the size of each draw, not the number of doses in the vial.
- Where do the TB-500 amounts on this page come from?
- They are amounts recorded for TB-500 in the compound library (https://peptidescalculator.com/compound-library/tb-500), which lists the sources behind them and labels each as clinical, preclinical or community-reported. They are shown for the arithmetic, not as recommendations, and the vial strength is the one suppliers list most often. Nothing on this page is medical advice.