How the Selank concentration calculation works
Concentration is the entered vial amount divided by the resulting solution volume. In this arithmetic example, 5 mg in 2 mL is 2.5 mg/mL. On a U-100 insulin syringe one unit represents 0.01 mL, so this example has 25 mcg per unit. An entered amount of 300 mcg therefore corresponds to 12 units.
The tables illustrate conversions, not a treatment schedule. They cannot determine whether a product is approved or suitable for human use. Follow product-specific instructions from your qualified prescriber or pharmacist for preparation, dose, device, and storage.
Selank conversion examples (5 mg in 2 mL)
| Dose | Units | mL | Doses per vial |
|---|---|---|---|
| 200 mcg | 8 | 0.08 | 25 |
| 300 mcg | 12 | 0.12 | 16 |
| 500 mcg | 20 | 0.2 | 10 |
Example amounts at 300 mcg per dose
| Vial | Water | Concentration | Units per dose | Doses |
|---|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 12 | 16 |
| 10 mg | 2 mL | 5 mg/mL | 6 | 33 |
Each amount shows its unit; the form starts in mcg. For a fixed amount and dose, doubling the resulting solution volume halves the concentration and doubles the calculated units. The arithmetic number of doses is unchanged. This relationship does not establish an appropriate preparation volume or syringe for a product.
Worked example
5 mg / 2 mL = 2.5 mg/mL = 2,500 mcg/mL. One unit = 0.01 mL = 25 mcg. 300 mcg / 25 mcg per unit = 12 units. The vial holds 5,000 / 300 = 16 doses, which at 7 per week is about 16 days.
See the general peptide reconstitution calculator for the formulas and mg-to-mcg conversions, and our calculator methodology and limitations. The FDA's report on compounded semaglutide dosing errors explains why concentration, units, and measurement instructions need to be confirmed with a health care provider or compounder.