How to Reconstitute Peptides (With Calculator)

What Is Reconstitution?

Most peptides come as a lyophilized (freeze-dried) powder in a glass vial. To use them, you add bacteriostatic water (water with 0.9% benzyl alcohol to prevent bacteria growth) and mix. This process is called reconstitution.

After reconstitution, the peptide is in solution at a specific concentration. You then draw up a precise amount using an insulin syringe to deliver your desired dose.

What You Need

• Vial of lyophilized peptide
• Vial of bacteriostatic water (BAC water)
• Insulin syringes (typically 1ml with 100-unit markings, 29-31 gauge needle)
• Alcohol prep pads

The Math — Step by Step

The three-step calculation:

1. Find the concentration: (peptide in mg × 1000) ÷ water in ml = mcg per ml
2. Find the ml needed: desired dose in mcg ÷ concentration (mcg/ml) = ml to inject
3. Find syringe units: ml × 100 = insulin syringe units

Reconstitution Calculator

Step-by-Step Reconstitution

1. Wash your hands. Clean workspace. Wipe both vial tops with alcohol.
2. Draw BAC water with a mixing syringe (larger needle OK here).
3. Inject water into the peptide vial. Aim the needle at the glass wall, not directly at the powder — peptides are fragile.
4. Swirl gently until dissolved. Do NOT shake aggressively. Most peptides take 30-60 seconds.
5. Label the vial with the date and concentration (e.g. "BPC-157 2500mcg/ml 2024-01-15").
6. Store reconstituted peptides in the fridge. Most last 2-4 weeks refrigerated. Some degrade faster.

Injecting the Final Dose

1. Use a fresh insulin syringe. Wipe the peptide vial top again.
2. Draw air into the syringe equal to your calculated volume (e.g. 10 units).
3. Inject air into the vial (equalizes pressure).
4. Turn vial upside down. Draw to your calculated unit mark.
5. Check for large air bubbles — flick to move them up, push out.
6. Inject subcutaneously: pinch skin (abdomen 2" from navel, upper thigh, back of arm), insert at 45-90°, push plunger slowly.