How to reconstitute a peptide safely

Mixing a freeze dried peptide with bacteriostatic water, one clean step at a time.

What you need

Before you start, set out everything on a clean, flat surface and wash your hands.

Your peptide vial
Bacteriostatic water (sterile water works for single use)
Alcohol wipes
A fresh insulin syringe
A sharps container for disposal

Work in a spot without a draft, and do not let the needle touch anything except the clean stopper and the water.

1. Start with a clean syringe

Open a new, sterile insulin syringe. Leave the cap on the needle until you are ready, and never touch the needle itself. If it brushes a surface, your skin, or anything else, set it aside and grab a fresh one.

2. Wipe both vial tops with alcohol

Swab the rubber stopper on the peptide vial and on the water vial with a fresh alcohol wipe. Give each a firm wipe, then let them air dry for a few seconds. This is the single easiest way to keep bacteria out of your vial.

3. Add air to the water vial

Pull the plunger back to draw in a volume of air equal to the water you plan to remove. Push that air into the bacteriostatic water vial first. This balances the pressure inside, so the water draws out smoothly instead of fighting a vacuum.

4. Draw the bacteriostatic water

Turn the water vial upside down with the needle still in, then pull the exact amount of water you planned. Tap out any large air bubbles and nudge them back into the vial.

5. Add the water to the peptide, slowly

Put the needle into the peptide vial and angle the tip against the inside glass wall. Let the water run down the side slowly. Do not blast it straight onto the powder, since a hard stream can damage the peptide.

6. Mix gently, never shake

Caution

Swirl the vial in a slow circle, or roll it between your palms, until the liquid turns clear. Never shake it. Shaking creates foam and shear forces that can break the peptide apart and lower its strength. Give it a minute or two to fully dissolve.

7. Wipe the stopper before every dose

Each time you go back to draw a dose, wipe the stopper with a fresh alcohol swab first. A vial you opened last week is not sterile on the outside anymore.

8. Clean your skin before you inject

Wipe the injection site with an alcohol swab and let it dry before the needle goes in. Rotate sites so you are not using the same spot every time, and drop the used syringe straight into your sharps container.

Safety notes

Warning

This is educational information, not medical advice. Use sterile technique every time, never share needles, and dispose of sharps properly. If a site becomes hot, swollen, or painful, or you feel feverish, stop and seek medical care. Signs of infection are not something to wait out.

Last reviewed 2026-07-07. Educational information only, not medical advice.