How to Reconstitute Peptides
A complete guide to mixing peptide powder with bacteriostatic water. Learn proper technique, storage, and dosing calculations.
What you'll need
Required
- Peptide vial (lyophilized powder)
- Bacteriostatic water (BAC water)
- Insulin syringe (29-31G)
- Alcohol swabs
Recommended
- Clean, flat work surface
- Good lighting
- Calculator or dosing app
- Refrigerator for storage
Important
Always use bacteriostatic water, not sterile water or saline. Bacteriostatic water contains a preservative (benzyl alcohol) that prevents bacterial growth and allows for multiple uses over time.
Step-by-step reconstitution
Prepare your workspace
Wash your hands thoroughly with soap and water. Clean your work surface with isopropyl alcohol or disinfectant. Gather all supplies before beginning.
Tips
- • Work in a clean, well-lit area
- • Avoid areas with drafts or air movement
- • Keep pets and children away
Clean the vial tops
Use an alcohol swab to thoroughly clean the rubber stopper on both the peptide vial and the bacteriostatic water vial. Allow to air dry for 10-15 seconds.
Tips
- • Don't blow on the vials to dry them faster
- • Always swab before each use, even if previously opened
Draw the bacteriostatic water
Draw your desired amount of bacteriostatic water into an insulin syringe. Common amounts are 1-3mL depending on your dosing preference. More water = easier to measure small doses.
Tips
- • Pull back the plunger slightly past your target amount, then push to the correct line
- • Hold syringe at eye level to read accurately
Inject water into peptide vial
Insert the needle through the rubber stopper of the peptide vial at a slight angle. Slowly inject the water down the side of the vial, allowing it to gently run down the glass wall onto the powder.
Tips
- • Go slow — take 30-60 seconds to inject all the water
- • Aim the needle at the glass wall, not the powder
Never spray water directly onto the powder. The pressure can damage the peptide. Let the water gently run down the side of the vial.
Allow the peptide to dissolve
Do not shake the vial. Set it upright in the refrigerator or at room temperature and allow the peptide to dissolve naturally. This usually takes 5-15 minutes.
Tips
- • Gentle rotation is okay if the powder hasn't fully dissolved after 15 minutes
- • The solution should be clear when fully dissolved
Never shake the vial. Shaking can denature (damage) the peptide structure. Gentle swirling is acceptable if needed.
Store properly
Once reconstituted, store the vial in the refrigerator (2-8°C / 36-46°F). Keep away from light. Most peptides remain stable for 4-6 weeks when properly stored.
Tips
- • Store upright, not on its side
- • Keep away from the freezer section
- • Label the vial with reconstitution date
Dosing calculator
Enter your peptide amount, water volume, and desired dose to calculate exactly how many insulin units (IU) to draw.
Dosing Calculator
Amount in your vial
Amount to add
Per injection
2.50
mg/mL concentration
0.100
mL per dose
10.0
insulin units (IU)
20
total doses per vial
Reading insulin syringes
Insulin syringes measure in “units” (IU), where 100 units = 1mL. So 10 units = 0.1mL, and 5 units = 0.05mL. The calculator above shows exactly how many units to draw for your desired dose.
Common peptide reference
Quick reference for typical reconstitution amounts and dosing for popular peptides.
| Peptide | Typical Vial | Water | Common Dose | Frequency |
|---|---|---|---|---|
| BPC-157 | 5mg | 2mL | 250-500mcg | 1-2x daily |
| TB-500 | 5mg | 2mL | 2-5mg | 2x weekly (loading), 1x weekly (maintenance) |
| Semaglutide | 3mg or 5mg | 3mL | 0.25-1mg | 1x weekly |
| Tirzepatide | 5mg or 10mg | 2mL | 2.5-5mg | 1x weekly |
| CJC-1295 (no DAC) | 2mg | 2mL | 100mcg | 1-3x daily |
| Ipamorelin | 5mg | 2.5mL | 200-300mcg | 2-3x daily |
* These are community-reported dosing ranges for informational purposes only. Always consult with a healthcare provider before using any peptides.
Storage guidelines
Before reconstitution
- • Store in freezer (-20°C) for long-term storage
- • Refrigerator (2-8°C) is fine for weeks to months
- • Keep away from light
- • Lyophilized powder is very stable
After reconstitution
- • Always refrigerate (2-8°C / 36-46°F)
- • Use within 4-6 weeks
- • Never freeze reconstituted peptide repeatedly
- • Store upright, away from light
Frequently Asked Questions
Common questions about peptide reconstitution
How long does reconstituted peptide last?
When stored properly in the refrigerator (2-8°C / 36-46°F), most reconstituted peptides remain stable for 4-6 weeks. BPC-157 is particularly stable and may last up to 8 weeks. Always check for cloudiness, particles, or color changes before use — discard if you notice any.
Can I use regular water instead of bacteriostatic water?
No. Regular water (including sterile water) lacks the benzyl alcohol preservative that prevents bacterial growth. Using regular sterile water means you must use the entire vial immediately or risk contamination. Bacteriostatic water allows for multiple uses over weeks.
What if I accidentally inject air bubbles into the vial?
Small air bubbles in the vial are normal and harmless. The peptide is in powder form before reconstitution. When drawing your dose, simply tap the syringe with the needle pointing up and push out any air before injecting.
How do I know if my peptide has gone bad?
Signs of degradation include: cloudiness or particles floating in the solution, color changes (peptide solutions should be clear), unusual smell, or visible mold/contamination. When in doubt, discard and use a fresh vial.
Can I freeze reconstituted peptides?
Most peptides can be frozen once reconstituted, which can extend shelf life to several months. However, repeated freeze-thaw cycles will degrade the peptide. If freezing, divide into single-use aliquots first. Not all peptides tolerate freezing equally — check specific guidance for your peptide.
What's the difference between bacteriostatic water and sterile water?
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows multiple uses over time. Sterile water is pure and must be used immediately. For multi-dose vials, always use bacteriostatic water.
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