Handling guide

Reconstitution, storage & measurement

General laboratory handling for lyophilized (freeze-dried) peptides. Compound-specific notes live on each monograph.

1. Before you start

Check the vial label: compound, amount (mg), and lot number. Keep the certificate of analysis with your records.
Let a refrigerated vial reach room temperature before opening to limit condensation inside the vial.
Work on a clean surface. Wipe vial stoppers with an alcohol swab and let them dry.

Diluent: bacteriostatic water (0.9% benzyl alcohol) for vials that will be accessed more than once; sterile water for single use. Some compounds need a specific solvent; this is noted on the monograph.
Technique: add diluent slowly down the inside wall of the vial, not directly onto the powder.
Mixing: swirl or roll gently. Don't shake. Agitation can damage peptide structure.
Check: the solution should be clear. Cloudiness or particles can indicate degradation or contamination.
Label it: record the date and the concentration (use the calculator).

State	Condition	General guidance
Lyophilized, long term	−20 °C, dark, dry	Most stable form. Avoid repeated freeze–thaw.
Lyophilized, short term	2–8 °C	Fine for weeks for most peptides; keep sealed.
Reconstituted	2–8 °C, protected from light	Use within the window listed on the monograph. Don't freeze unless specified.

Main causes of degradation: heat, light, moisture, repeated freeze–thaw cycles, and physical shock.

U-100 insulin syringes: 1 mL = 100 units. 0.1 mL = 10 units.
1 mg = 1,000 mcg. Unit confusion between mg and mcg is the most common calculation error.
Very small volumes are hard to measure accurately. A lower concentration (more diluent) makes them larger and easier to read.

Use a rated sharps container for needles and syringes, and follow local rules for disposal of sharps and chemical waste.