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Guide · 6 min

Reconstitution, the right way

How to mix lyophilized peptides with bacteriostatic water, figure your concentration, and draw a clean dose.

What reconstitution actually is

Most peptides ship as a freeze-dried (lyophilized) powder because they are unstable in liquid. Reconstituting means adding a sterile liquid — almost always bacteriostatic water — to dissolve the powder into a solution you can draw and inject. The amount of water you add is your choice, and it sets the concentration.

Why the water volume sets your dose

A 5 mg vial mixed with 1 mL of water gives 5 mg/mL; the same vial mixed with 2 mL gives 2.5 mg/mL. The peptide amount never changes — only the concentration does. More water means each unit on the syringe holds less peptide, which makes small doses easier to measure accurately.

Adding the water cleanly

Wipe both stoppers with alcohol. Draw your bacteriostatic water, then let it run slowly down the inside wall of the vial rather than blasting it directly onto the powder — peptides are delicate. Swirl gently to dissolve; never shake. If it does not fully clear, give it a few minutes in the fridge.

Reading the draw on an insulin syringe

Insulin syringes are marked in units (100 units = 1 mL). At 5 mg/mL, 20 units (0.2 mL) is 1 mg. The dose calculator does this math for you — enter the vial size, your water volume, and the dose you want, and it returns the exact units to pull.

After mixing

Label the vial with the date and concentration, keep it refrigerated, and protect it from light. Reconstituted peptides have a limited shelf life — the vial tracker can flag when one is getting old.

Educational only — harm-reduction information, not medical advice.