How to Calculate Peptide Dosing from Concentration and Volume

Accurate dosing calculations are the foundation of meaningful protocol tracking. If your math is off when converting between milligrams, micrograms, and milliliters, every entry in your log is wrong by the same factor. This makes it impossible to assess whether a protocol is working as intended or to share reliable data with a healthcare provider. The math itself is straightforward once you understand the relationship between the amount of compound in a vial, the volume of solvent you add, and the resulting concentration. This content is for educational and research documentation purposes only. Always work with a qualified healthcare professional for any protocol involving injectable compounds.

After reconstitution, the concentration of your solution equals the total amount of compound divided by the total volume of solvent added. If a vial contains 5 mg of a compound and you add 2 mL of bacteriostatic water, the concentration is 5 mg / 2 mL = 2.5 mg/mL. To calculate how much volume to draw for a specific dose, rearrange the formula: Volume = Desired Dose / Concentration. If you want 250 mcg (0.25 mg) from a 2.5 mg/mL solution, you need 0.25 / 2.5 = 0.1 mL. On an insulin syringe marked in units (where 100 units = 1 mL), 0.1 mL equals 10 units.

The most common source of dosing errors is mixing up units. Key conversions: 1 mg = 1,000 mcg. 1 mL = 100 units on a standard U-100 insulin syringe. Always convert everything to the same unit system before calculating. If a protocol calls for a dose in mcg but your concentration is in mg/mL, convert one to match the other before dividing. Example: a protocol calls for 200 mcg from a vial reconstituted to 2.5 mg/mL. Convert 200 mcg to 0.2 mg. Then 0.2 mg / 2.5 mg/mL = 0.08 mL = 8 units on an insulin syringe.

Step 1: Record the total amount of compound in the vial (usually printed on the label, in mg). Step 2: Record the volume of bacteriostatic water you added during reconstitution (in mL). Step 3: Calculate concentration: total mg / total mL. Step 4: Convert your desired dose to the same unit as the concentration (mg or mcg). Step 5: Calculate volume: desired dose / concentration. Step 6: Convert mL to syringe units if using an insulin syringe (multiply mL by 100). Step 7: Log the dose, volume, concentration, and timestamp in your protocol tracker. Following this sequence every time prevents the most common errors.

The most frequent error is forgetting to convert mcg to mg before dividing, which produces a dose 1,000x larger or smaller than intended. The second most common is using the wrong reconstitution volume — if you added 2.5 mL but calculated based on 2 mL, every dose is 20% off. Third, syringe unit confusion: not all syringes are U-100. Verify the syringe markings before drawing. Fourth, assuming all vials contain the same amount — different vendors sell different quantities even for the same compound. Always check the label. Dosed includes a built-in reconstitution calculator that handles the math for you, reducing the risk of conversion errors and keeping your dose logs consistent.