Most peptides arrive as a dry, freeze-dried powder. Before you can measure a dose, you add liquid to the vial. That step is called reconstitution. It takes about five minutes once you know the routine, and doing it carefully protects both the peptide and you.
What you need
- The peptide vial, with the amount (for example 5 mg or 10 mg) on the label.
- Bacteriostatic water (BAC water): sterile water with 0.9% benzyl alcohol, which lets a mixed vial be used for several weeks.
- A syringe to draw the water: a 1 mL or 3 mL syringe makes this easier than a small insulin syringe.
- U-100 insulin syringes for dosing.
- Alcohol swabs, a clean surface and a sharps container.
- A pen or label to mark the vial.
Step 1: Decide how much water to add
The amount of water does not change how much peptide is in the vial. It only changes how concentrated the liquid is, and so how many units you draw for each dose. Pick an amount that makes your dose easy to measure.
| 5 mg vial mixed with | Concentration | A 250 mcg dose is |
|---|---|---|
| 1 mL | 5 mg/mL | 5 units |
| 2 mL | 2.5 mg/mL | 10 units |
| 3 mL | 1.67 mg/mL | 15 units |
A good rule of thumb: aim for each dose to land between about 5 and 50 units. Very small volumes (under 2–3 units) are hard to measure accurately. Very large volumes mean bigger, less comfortable injections and may not fit in your syringe. The Peptide Calculator shows the result for any combination before you mix.
Step 2: Prepare
- Wash your hands well and clean your work surface.
- If the vial was in the fridge or freezer, let it come to room temperature for 10–15 minutes.
- Flip off the plastic caps and wipe both rubber stoppers (peptide and water) with an alcohol swab. Let them air-dry.
Step 3: Draw the water
- Pull the syringe plunger back to the amount of water you plan to add, filling it with air.
- Push the needle into the BAC water vial and inject the air. This keeps the pressure even and makes drawing easier.
- Turn the vial upside down and slowly draw the planned amount of water. Tap out any large bubbles.
Step 4: Add the water to the peptide
- Insert the needle into the peptide vial at an angle.
- Let the water run slowly down the inside wall of the glass, not straight onto the powder.
- If the vial pulls the plunger in on its own, that is normal: many vials are sealed under a slight vacuum.
Step 5: Dissolve gently
Gently swirl or roll the vial between your palms until the powder dissolves. Do not shake it. Shaking can damage fragile peptides and creates foam. Most peptides dissolve within a minute or two; some take longer. If a little powder remains, let the vial sit in the fridge for 15–30 minutes and swirl again.
A few compounds, including AOD-9604, ARA-290, Dihexa and SLU-PP-332, do not dissolve easily in water. For these, follow the seller’s mixing instructions.
Step 6: Check, label and store
- The finished liquid should be clear and colorless (copper peptides such as GHK-Cu are naturally blue).
- Write the date and the concentration on the vial, for example “2.5 mg/mL, mixed 10/25.”
- Store it upright in the refrigerator at 2–8 °C (36–46 °F), away from light. Do not freeze a mixed vial.
Drawing a dose
- Wipe the stopper with a fresh alcohol swab.
- Pull the insulin syringe plunger back to your dose in units, inject that air into the vial, then turn the vial upside down and draw your dose.
- Tap out bubbles and push the plunger to the exact line.
- Use a new syringe for every dose, and never share syringes or vials.
Bacteriostatic water or sterile water?
Bacteriostatic water contains a preservative, so a mixed vial can be used for multiple doses, usually for up to about four weeks depending on the peptide. Sterile water has no preservative and is meant for a single use; once opened, it should not be stored for later doses. For multi-dose vials, bacteriostatic water is the standard choice.
Troubleshooting
| Problem | What to do |
|---|---|
| Cloudy liquid or floating particles | Do not use it. Clear liquid is the standard. |
| Foam or bubbles after mixing | Let it rest in the fridge until the foam settles. Avoid shaking next time. |
| Powder will not dissolve | Rest it in the fridge and swirl again. If it still will not dissolve, check the seller’s mixing instructions. |
| Water spurts back out or the plunger resists | The vial has built up pressure. Pull a little air out before adding more water. |
| No vacuum when you first add water | Not always a problem, but note it. A missing or loose seal is worth raising with the seller. |
| Added the wrong amount of water | The peptide is fine. Use the calculator with the amount you actually added. |