What Is Reconstitution?
Reconstitution is the process of adding a liquid (solvent) to a freeze-dried (lyophilized) peptide powder to create an injectable solution. Most research peptides ship as a dry powder in a sealed vial — you need to add bacteriostatic water before they can be used.
The process is straightforward, but doing it wrong can destroy your peptide, introduce contamination, or result in inaccurate dosing. This guide walks through every step.
What You'll Need
Lyophilized Peptide Vial
The sealed vial containing your freeze-dried peptide powder. Should be a white or off-white cake or powder. If it's a clear liquid, it's already reconstituted.
Bacteriostatic Water (BAC Water)
Sterile water with 0.9% benzyl alcohol as a preservative. This is the standard solvent for peptide reconstitution. Do NOT use tap water, distilled water, or saline.
Alcohol Swabs
70% isopropyl alcohol pads to sterilize vial tops before puncturing. Non-negotiable for contamination prevention.
Syringes
A larger syringe (3mL, 18-21ga needle) for transferring BAC water, plus insulin syringes (1mL, 29-31ga) for drawing doses after reconstitution.
BAC Water Ratios & Dosing Math
The amount of BAC water you add determines the concentration of your solution. More water = weaker concentration = easier to measure small doses. Here are common ratios:
| Peptide Amount | BAC Water Added | Concentration | Per 10 Units (0.1mL) |
|---|---|---|---|
| 5 mg | 1 mL | 5,000 mcg/mL | 500 mcg |
| 5 mg | 2 mL | 2,500 mcg/mL | 250 mcg |
| 5 mg | 2.5 mL | 2,000 mcg/mL | 200 mcg |
| 10 mg | 2 mL | 5,000 mcg/mL | 500 mcg |
| 10 mg | 5 mL | 2,000 mcg/mL | 200 mcg |
The Simple Formula: Concentration (mcg/mL) = Peptide amount (mcg) ÷ BAC water (mL). For a 5mg vial with 2mL water: 5,000 mcg ÷ 2 = 2,500 mcg/mL. Each "unit" on a 100-unit insulin syringe = 25 mcg. Use our Peptide Calculator for instant math.
(lyophilized)
(0.9% benzyl alcohol)
(refrigerate)
Step-by-Step Reconstitution
Wash Your Hands
Thorough handwashing with soap and water for at least 20 seconds. This is sterile technique — contamination is your enemy.
Swab All Vial Tops
Use alcohol swabs to clean the rubber stopper on both the peptide vial and the BAC water vial. Let air dry for 10-15 seconds. Don't blow on them.
Draw BAC Water
Using a 3mL syringe with an 18-21ga needle, draw your desired amount of bacteriostatic water. Pull air into the syringe first (equal to the water volume), inject air into the BAC water vial, then draw the water out. This equalizes pressure.
Inject Water Into Peptide Vial — SLOWLY
This is the critical step. Insert the needle into the peptide vial and aim it at the glass wall — NOT directly at the powder. Depress the plunger slowly, letting the water trickle down the side of the vial. This should take 30-60 seconds for 2mL.
Let It Dissolve — Don't Shake
Set the vial on a flat surface and let the water gently dissolve the powder. You can tilt the vial slightly to help, but never shake it. Shaking creates foam and can denature (damage) the peptide. Most dissolve in 1-3 minutes.
Inspect the Solution
Once dissolved, the solution should be clear or very slightly hazy. If there are visible particles that won't dissolve after 5 minutes, the peptide may have been damaged in shipping. Don't use cloudy solutions.
Label and Refrigerate
Write the peptide name, concentration, and reconstitution date on the vial. Store at 2-8°C (36-46°F) in the refrigerator. Use within 28-30 days.
Common Mistakes to Avoid
Spraying Water Directly on Powder
Always aim at the vial wall. Direct streams can damage the peptide structure through physical force.
Shaking the Vial
Shaking denatures proteins. Gentle swirling is OK if needed, but patience is better. Let gravity do the work.
Using Regular Sterile Water
Sterile water lacks the benzyl alcohol preservative. If you must use it, the reconstituted peptide must be used within 24 hours.
Skipping Alcohol Swabs
Bacterial contamination is the #1 cause of injection site infections. Always swab vial tops — every single time.
Leaving at Room Temperature
Reconstituted peptides degrade rapidly at room temperature. Refrigerate immediately after mixing. Never freeze reconstituted solutions.
Wrong Dosing Math
Double-check your concentration calculation. Using the wrong ratio can mean 2x or 0.5x your intended dose. Use a peptide calculator.
Storage After Reconstitution
Once mixed, peptides are in a fragile state. Follow these rules:
- Temperature: 2-8°C (36-46°F) — standard refrigerator temperature
- Light: Keep in the original vial. Amber vials provide UV protection. If clear, store away from direct light.
- Duration: Use within 28-30 days with BAC water. Label the date.
- Never freeze reconstituted peptides — ice crystals destroy the peptide structure
- Travel: Use an insulated pouch with ice packs. Don't leave in a hot car. TSA allows medical liquids with documentation.
Signs your peptide has gone bad: Cloudiness, visible particles, unusual color change, or a strange smell. When in doubt, discard it. A degraded peptide won't work and could cause injection site reactions.
Key Takeaways
✅ Do This
- Use bacteriostatic water (0.9% benzyl alcohol)
- Aim water at the vial wall, not the powder
- Let dissolve naturally — don't shake
- Swab all vial tops with alcohol before each use
- Refrigerate immediately after reconstitution
- Label with name, concentration, and date
- Use within 28-30 days
⚠️ Avoid This
- Don't shake — ever
- Don't spray water directly on powder
- Don't use tap/distilled water
- Don't skip sterilization
- Don't freeze reconstituted peptides
- Don't leave at room temperature
- Don't reuse syringes