Reconstitution

Research peptides arrive as a lyophilized (freeze-dried) powder, and reconstitution is the step where you turn that powder back into a liquid you can actually inject. You add a measured amount of sterile liquid — most often bacteriostatic water — to the vial, and the powder dissolves into a solution.

It’s the same everyday idea as mixing powdered drink or reconstituting concentrate: add the liquid, and the dry stuff becomes usable again. The difference is that here the amount of liquid you add isn’t casual — it sets the concentration, which decides how much liquid equals your intended dose.

That’s the part worth slowing down for. Adding 1 mL of water to a 5 mg vial gives a different concentration than adding 2 mL, and the syringe markings mean different amounts as a result. This is exactly what a reconstitution calculator is for — it does the arithmetic so a given number of units on the syringe lines up with the dose you want.

For a concrete example, tesamorelin makes the concentration math visible: the current EGRIFTA SV label starts with a 2 mg lyophilized vial and 0.5 mL of sterile water, producing a concentration of 2 mg per 0.5 mL. It then identifies 1.4 mg as 0.35 mL of that solution, which shows how the powder amount and added liquid determine the volume measured in the syringe. The same label tells users to roll rather than shake the vial and use the solution immediately after mixing. That last detail matters: this tesamorelin formulation should not be refrigerated after reconstitution, so product-specific instructions take priority over a general storage rule.

A few sterility basics matter: wipe the vial stopper with alcohol, add the water gently down the side rather than blasting the powder, and swirl (don’t shake hard) to dissolve. Once reconstituted, most peptides live in the fridge.