Reconstitution

Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder in a sterile diluent — most commonly bacteriostatic water — to produce an injectable solution. The volume of diluent chosen determines the final concentration in mg/mL, which in turn determines how many ‘units’ on a U-100 insulin syringe correspond to a given dose in micrograms.

The standard procedure is: pull the diluent into a sterile syringe, inject it slowly down the side of the vial wall (not directly onto the lyophilized cake), gently swirl until fully dissolved, and refrigerate. Most reconstituted peptides are stable refrigerated for 14–30 days, depending on the compound.

Reconstitution math is the single most error-prone step in self-administered peptide research. Use a dedicated reconstitution calculator rather than trying to do dimensional analysis at the bench.