How to Use Peptides: Reconstitution, Dosing, and Injection

Gather your supplies

You need the lyophilised (freeze-dried) peptide vial, bacteriostatic water (BW), a 1ml insulin syringe, and an alcohol wipe. Bacteriostatic water — not sterile water, not tap water — is the correct reconstitution solvent for storage. It contains 0.9% benzyl alcohol which prevents bacterial growth in the vial.

Wipe both vial tops with alcohol

Use an alcohol swab on the rubber septum of both the peptide vial and the bacteriostatic water vial. Allow 30 seconds to dry. This is a sterility step — don't skip it.

Draw the bacteriostatic water

Using the insulin syringe, draw your intended volume of bacteriostatic water. A common starting point is 1ml per 5mg vial, which gives a concentration of 5mg/ml (5000mcg/ml). Adjust based on your dosing calculation — use the calculator on this site to find the exact volume you need.

Inject the BW into the peptide vial slowly

Insert the needle through the rubber septum of the peptide vial and angle it so the bacteriostatic water runs down the inside wall of the glass — not directly onto the lyophilised powder. This prevents foaming and possible peptide degradation. Inject slowly.

Do not shake — swirl gently

The peptide will dissolve quickly. Gently swirl or rotate the vial until the solution is clear. Never shake vigorously — peptides have fragile tertiary structures that mechanical agitation can disrupt.

Store refrigerated, not frozen

Reconstituted peptide solution should be stored in the refrigerator (2–8°C). Do not freeze. Most reconstituted peptides remain stable for 4–6 weeks refrigerated. Lyophilised (unmixed) vials can be stored frozen long-term before reconstitution.

Calculate your dose precisely

Use a calculator before every draw. For example: if you have 5mg BPC-157 in 1ml BW (5000mcg/ml) and want a 250mcg dose, you need 0.05ml (5 units on a 100-unit insulin syringe). Small errors in peptide dosing are easy to make and important to avoid.

Choose your injection site

Subcutaneous (SubQ) injection is the standard for most research peptides. Common sites: lower abdomen (1–2 inches from the navel), outer thigh, or upper outer arm. Pinch approximately one inch of skin between thumb and forefinger to lift subcutaneous tissue.

Insert at 45–90 degrees

For subcutaneous injection with an insulin syringe (which has a very short needle), insert at a 45-degree angle into the pinched skin. Thicker subcutaneous tissue allows 90 degrees. Inject slowly and steadily.

Withdraw and apply light pressure

After injection, withdraw the needle smoothly and apply gentle pressure with a clean cotton ball or gauze for a few seconds. Do not rub — this can spread the compound away from the intended site.

Rotate sites

Always rotate injection sites to prevent localised tissue irritation, lipodystrophy, or scarring. Keep a simple log of which site you used.