A 6-step guide for safely mixing semaglutide, tirzepatide, and other peptide vials with bacteriostatic water.
Peptide vial, bacteriostatic water (BAC water), 3 mL reconstitution syringe, alcohol swabs, 1 mL U100 insulin syringe. Never use plain sterile water — only BAC water extends shelf life.
Wipe the rubber septum of both vials with alcohol swabs. Let dry 30 seconds before inserting any needle. Work on a clean, flat surface.
Draw your chosen amount of BAC water (commonly 2 mL). Use the Reconstitution Calculator to choose the volume that gives you a convenient concentration.
Insert the needle at an angle and let the BAC water run down the glass wall — never shoot it onto the powder. Injecting too fast can denature the peptide.
Gently swirl until powder dissolves fully. Solution should be clear. If cloudy, do not use. Vigorous shaking breaks peptide bonds and reduces potency.
Refrigerate immediately at 36–46°F (2–8°C). Protect from light. Use within 28 days. Never freeze. A vial case keeps vials secure and temperature-stable.
Answers to the questions we see most often.
Most use 2 mL, giving 2.5 mg/mL. At 0.25 mg starting dose, inject 0.1 mL (10 units). Use the calculator to confirm.
Yes, but recalculate concentration. Adding more dilutes the vial — your previous unit markings are no longer correct.
Generally 28 days refrigerated with bacteriostatic water. The BAC acts as a preservative. Discard after 28 days regardless.
A 1 mL U100 insulin syringe (29–31 gauge, 5/16" or 8mm needle) for subcutaneous injection. Each unit = 0.01 mL.
Yes, identical principles. Common vials: 5 mg, 10 mg, 15 mg. Use 2 mL BAC water with 5 mg or 10 mg vials for clean math.
Refrigerated, protected from light, in a secure case. A hard-shell case prevents breakage and protects the rubber septum.
Reconstituted GLP-1 peptides are delicate. A purpose-built case keeps them upright, protected from light, and safe during travel.