Peptide Concentration and Volume: How the Reconstitution Math Works

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. That concentration is a property of the mixed vial. It is what later lets a volume be translated into syringe units (on a U-100 syringe, 100 units = 1 mL), but the dose itself — how much of the compound to administer — is set by your prescriber or product label, not by this page.

The most dangerous source of error is mixing up units, so this is worth understanding clearly. Key conversions: 1 mg = 1,000 mcg, and 1 mL = 100 units on a standard U-100 insulin syringe. The classic costly mistake is reading a microgram figure as milligrams (or vice versa) — a 1,000-fold error. Always make sure the dose and the concentration are expressed in the same unit before doing any arithmetic, and verify the unit on your product and with your prescriber. This page explains the unit relationships; it does not compute a personal dose.

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: Record that concentration with the vial so you always know what is in each mL. Step 5: When administering the dose your prescriber or product label has set, make sure the dose and the concentration are in the same unit before checking it against the syringe. Step 6: Log the administered dose, the concentration, and the timestamp in your protocol tracker. Recording these consistently keeps your log accurate and makes the record useful for your provider.

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 reconstitution helper that records your concentration from the vial amount and water you enter, keeping your logs consistent.