Enter your vial size and bacteriostatic water to get concentration, draw volume, and insulin-syringe units instantly.
Working with lyophilized research peptides means converting a dry powder into a precisely measurable solution before any quantitative work can begin. This page combines a live reconstitution calculator with a plain-language explanation of the math, so a vial of powder can be turned into a known concentration and an accurate withdrawal volume in a few seconds. Everything here is intended for in-vitro laboratory research only.
Research peptides are shipped as a freeze-dried solid because the dry state is far more stable during storage and transport than a liquid. Reconstitution is simply the step of dissolving that solid in a sterile diluent so the peptide is evenly distributed throughout a liquid. Once dissolved, the total mass of peptide is unchanged — it is now spread through a known volume, which is what makes it possible to measure small, repeatable amounts. The two numbers that matter going in are the mass of peptide in the vial (in milligrams) and the volume of diluent you add (in milliliters).
The diluent of choice in most reconstitution work is bacteriostatic water — sterile water with 0.9% benzyl alcohol added as a preservative. The benzyl alcohol inhibits bacterial growth, which is what allows a single vial to be accessed more than once without the solution spoiling between withdrawals. The exact volume of bacteriostatic water you add is a free choice, and it directly sets the concentration: adding more water dilutes the peptide and makes each unit on the syringe correspond to a smaller amount, while adding less water concentrates it. Choosing a round volume (for example 1 mL or 2 mL) usually makes the downstream syringe math cleaner.
Concentration is mass divided by volume. If you reconstitute a 5 mg vial with 2 mL of bacteriostatic water, the concentration is 5 ÷ 2 = 2.5 mg/mL, equivalent to 2,500 mcg/mL (there are 1,000 micrograms in a milligram). To find how much solution corresponds to a target amount, you reverse the operation and divide the desired amount by the concentration. A 250 mcg target from a 2.5 mg/mL solution works out to 0.25 mg ÷ 2.5 mg/mL = 0.1 mL. Because a U-100 insulin syringe is graduated so that 1 mL equals 100 units, that same 0.1 mL is read off as 10 units on the barrel. The calculator below runs all of these conversions live as you type, reports concentration in both mg/mL and mcg/mL, and shows the draw volume alongside its U-100 syringe equivalent so nothing has to be done by hand.
Concentration
—
—
Volume to draw
—
for the desired dose
U-100 insulin syringe
—
On a U-100 syringe (1 mL = 100 units)
For laboratory measurement/research only — not medical or human-dosing advice.
Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder into a sterile liquid so it can be accurately measured. Research peptides ship as a dry solid in a sealed vial; adding a known volume of diluent turns that solid into a solution of known concentration that can be drawn in precise amounts.
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, an agent that inhibits the growth of bacteria. In a research setting it is commonly chosen as the diluent because the preservative allows a reconstituted solution to remain stable across multiple withdrawals from the same vial, unlike plain sterile water.
Concentration equals the peptide mass divided by the volume of water added. For example, 5 mg of peptide reconstituted with 2 mL of bacteriostatic water gives 2.5 mg/mL, which is the same as 2,500 mcg/mL. The calculator on this page reports both units automatically.
Divide the desired amount by the concentration. With a 2.5 mg/mL solution, a 250 mcg target is 0.25 mg ÷ 2.5 mg/mL = 0.1 mL. On a U-100 insulin syringe, where 1 mL equals 100 units, 0.1 mL reads as 10 units.
Reconstituted peptides are generally aliquoted and stored cold, often at -20°C or -80°C, to preserve stability and to avoid repeated freeze-thaw cycles. Always follow the storage guidance and Certificate of Analysis supplied with the specific compound.