TB-500 reconstitution calculator

A 5 mg TB-500 vial mixed with 2 mL of bacteriostatic water gives 2.5 mg/mL. The 2 mg illustrative dose pulls 0.8 mL or 80 units — almost a full insulin syringe. With 2 doses per week per the typical loading protocol, that vial covers 1 week.

In the worked example below, a 5 mg vial of TB-500 reconstituted with 2 mL of BAC water produces a concentration of 2.5 mg/mL. To draw the example dose of 2 mg from that vial you pull 0.80 mL — about 80 units on a standard insulin syringe. Change any input and the rest updates instantly so you can pre-plan a vial before you ever touch a needle.

Vial size, diluent volume, and dose are the three inputs that genuinely change the answer. Doses-per-vial is a derived output — it's the vial mg divided by the dose mg, rounded down. The most common edge case is a tiny dose: at very high concentration, a 0.1 mL draw is only a few units on the syringe, which is hard to read accurately. If your unit count drops below five, consider reconstituting the next vial with more BAC water so each dose covers a larger volume.

The calculation for a TB-500 dose requires careful attention to concentration. For an example scenario, if a 5 mg vial of lyophilized powder is reconstituted with 2 mL of bacteriostatic water, the resulting solution has a concentration of 2.5 mg per mL. To prepare a 2 mg dose, one would need to calculate the required volume: (2 mg dose) / (2.5 mg/mL concentration) = 0.8 mL. This volume directly converts to 80 units on a U-100 insulin syringe. Using a peptide calculator automates this conversion, ensuring accuracy when translating a target milligram dose into a unit measurement for administration.

The volume of diluent used is a critical variable due to the large dose size of TB-500. Using a smaller volume, like 1 mL for a 5 mg vial, creates a highly concentrated solution (5 mg/mL) that allows for a smaller total injection volume; a 2 mg dose in this case would be only 0.4 mL or 40 units. Conversely, using a larger diluent volume, such as 3 mL, results in a more dilute solution (1.67 mg/mL), which requires a larger injection volume but can make it mechanically easier to measure small adjustments to a dose with higher precision on the syringe barrel. This choice is a trade-off between injection comfort and measurement granularity that should be documented in a log.