Read this first
This is a general explanation, not medical instruction. If a prescriber or pharmacist has given you a product, follow their directions and the product insert. They should also show you how to handle needles and inject safely.
What reconstitution means
Many peptides are supplied as a dry, freeze-dried (lyophilized) powder because it stays stable much longer than a liquid. Before use, the powder is dissolved in a measured amount of liquid, usually bacteriostatic water. The amount of liquid you add sets the concentration, and the concentration decides how many units on the syringe hold your dose.
Supplies usually involved
- The peptide vial, with its total amount (for example 5 mg) on the label.
- Bacteriostatic water (sterile water with 0.9% benzyl alcohol), unless the product specifies another diluent.
- A syringe for measuring the water, and U-100 insulin syringes for doses.
- Alcohol swabs and a sharps container.
- A pen to label the vial.
Step 1: Decide how much water to add
Pick a volume before you start. A good choice makes your dose a round number of units on the syringe you use. Enter your vial size, dose and preferred units in the BAC water calculator to get the exact volume. Common choices for small vials are 1 to 3 mL.
Step 2: Prepare
- Wash your hands and work on a clean surface.
- Let refrigerated vials come to room temperature.
- Remove the plastic caps and wipe each rubber stopper with a fresh alcohol swab. Let it dry.
Step 3: Add the water slowly
- Draw the chosen volume of bacteriostatic water.
- Insert the needle through the peptide vial's stopper and let the water run slowly down the inside wall of the vial, not directly onto the powder.
- Remove the needle and dispose of it safely.
Step 4: Dissolve gently
Swirl or roll the vial slowly until the powder has fully dissolved. Do not shake it. The solution should be clear. If it stays cloudy or has particles, do not use it.
Step 5: Label it
Write the date and the concentration on the vial, for example 5 mg / 2 mL = 2,500 mcg/mL (25 mcg per unit). This one habit prevents most later mistakes, especially when you have vials of different sizes.
Step 6: Work out each dose
Use the reconstitution calculator with your vial size, the water you added and your dose. It shows the units to draw and draws the line on a syringe. The syringe units chart explains how each syringe size is marked.
Storage
Follow the product's instructions. Reconstituted peptides are generally kept in the refrigerator, at about 36 to 46 °F (2 to 8 °C), away from light, and are not frozen. Discard the vial by the date the product information gives.
Reconstitution questions
Should I shake the vial to dissolve the powder?
No. Swirl or roll it gently between your fingers. Vigorous shaking can create foam and may damage delicate molecules. Most powders dissolve within a few minutes; some take longer.
What if the solution is cloudy or has particles?
A properly reconstituted solution is usually clear. If it stays cloudy, has visible particles or changes color, do not use it, and check with the supplier or your pharmacist.
How long does a reconstituted vial last?
It depends on the product and the diluent. Follow the product's storage instructions. As a general rule, vials mixed with bacteriostatic water are kept refrigerated and protected from light, and are not frozen.
Why does the vial resist when I add water?
Vials are sealed, so adding liquid raises the pressure inside. Add the water slowly. Some people let a small amount of air escape back into the syringe as they go; follow the technique you were taught.