Reconstitution is the process of adding liquid to a freeze-dried (lyophilized) peptide powder to create an injectable solution. Peptides ship as dry powder because they degrade quickly in liquid form. You mix them yourself right before you begin using them.
This guide covers the full process from equipment to injection-ready solution.
What You Need
Gather everything before you start. Working with a clean, organized surface reduces contamination risk.
Required equipment:
- Bacteriostatic water (BAC water) - Sterile water containing 0.9% benzyl alcohol as a preservative. This is the standard for multi-dose vials. Available in 10ml or 30ml vials.
- Insulin syringes - 1ml (100-unit) syringes with 29g or 30g needles for drawing and injecting. You need at least two: one for reconstitution, one for dosing.
- Alcohol swabs - 70% isopropyl alcohol pads for sterilizing vial tops.
- Peptide vial - Your lyophilized peptide. Should contain a small disc or puck of white/off-white powder at the bottom.
- Sharps container - For safe disposal of used needles. Never recap and reuse needles.
Optional but helpful:
- Nitrile gloves
- Clean paper towels or lint-free wipes
- A pen and label tape for marking vials with the reconstitution date
Step-by-Step Process
Step 1: Clean your workspace
Wipe down your surface with 70% isopropyl alcohol. Wash your hands thoroughly. Put on gloves if you have them.
Step 2: Let vials reach room temperature
Remove your peptide vial and BAC water from refrigeration. Let them sit for 5-10 minutes. Cold vials can cause pressure differences that make drawing water difficult.
Step 3: Determine your water volume
The amount of water you add determines your concentration. For example, adding 2ml of water to a 5mg vial of BPC-157 gives you 2,500mcg per ml (2.5mg/ml). Adding 1ml to the same vial gives 5,000mcg per ml.
More water means easier measurement of small doses. Less water means smaller injection volumes. Most peptides work well with 1-2ml. Check your peptide's recommended water volume on its calculator page.
Step 4: Swab the vial tops
Use a fresh alcohol swab on the rubber stopper of both the BAC water vial and the peptide vial. Let the alcohol dry for a few seconds. Do not blow on them.
Step 5: Draw bacteriostatic water
Insert the syringe needle into the BAC water vial. Tip the vial upside down. Pull the plunger back to your desired volume. Remove any air bubbles by tapping the syringe and pushing them back into the vial.
Step 6: Add water to the peptide vial
Insert the needle into the peptide vial at a slight angle. Do not aim the stream directly at the powder. Instead, let the water trickle down the inside wall of the vial. Push the plunger slowly. Rushing this step can damage the peptide.
Step 7: Let it dissolve
Do not shake the vial. Set it down and let the water work its way through the powder naturally. You can tilt the vial gently or roll it between your palms. Most peptides dissolve within 1-3 minutes. Some take up to 10 minutes.
The solution should be clear when fully dissolved. A slightly yellow tint is normal for some peptides (like GHK-Cu). Cloudiness or visible particles after 10 minutes of gentle swirling is a problem.
Step 8: Label and store
Write the peptide name, concentration, and today's date on the vial. Store immediately at 2-8°C (standard refrigerator). See our storage guide for full details.
Common Mistakes
Shaking the vial. This is the most frequent error. Aggressive shaking creates bubbles and can denature the peptide's structure, reducing potency. Gentle swirling only.
Using the wrong water. Never use saline, distilled water from a store, or tap water. Only bacteriostatic water (for multi-dose vials) or sterile water for injection (for single-use). See our BAC water vs sterile water guide.
Squirting water directly onto the powder. The force of the stream can damage the peptide. Aim down the glass wall and let gravity do the work.
Reusing needles. Each needle dulls after a single use. A dull needle causes more tissue damage and increases infection risk. Use a fresh needle every time.
Forgetting to swab the stopper. The rubber stopper is not sterile after the factory seal is removed. Always swab with alcohol before every insertion.
Leaving reconstituted peptide at room temperature. Peptides degrade rapidly outside refrigeration. Put the vial back in the fridge as soon as you draw your dose. Even 30 minutes at room temperature repeatedly will shorten shelf life.
After Reconstitution
Your peptide is now ready to dose. Use the calculator for your specific peptide to determine how many units to draw on your insulin syringe:
- BPC-157 calculator
- Semaglutide calculator
- Tirzepatide calculator
- TB-500 calculator
- CJC-1295/Ipamorelin calculator
Each calculator factors in your vial size, water volume, and desired dose to tell you exactly how many units to draw.