How to Reconstitute
Research Peptides

What You'll Need

• Lyophilized peptide vial — freeze-dried powder from Purity Peptides
• Bacteriostatic Water (BAC water) — 0.9% benzyl alcohol in sterile water; prevents microbial growth and extends shelf life of reconstituted peptide
• Insulin syringes — 0.3mL or 1mL, 28–31 gauge; precision markings for small volumes
• Alcohol swabs — to sterilize vial tops before each use

Step-by-Step Reconstitution

1. Calculate your target concentrationUse the calculator below (or the formula: mL of BAC water = mg in vial ÷ target mg/mL). Common targets: 2mg/mL for most peptides, 1mg/mL for high-dose compounds.
2. Clean both vial topsWipe the rubber stopper on both the peptide vial and the BAC water vial with a fresh alcohol swab. Let air dry for 5–10 seconds.
3. Draw bacteriostatic waterInsert the syringe needle through the center of the BAC water vial stopper. Draw up the calculated volume slowly. Remove needle.
4. Inject into the peptide vial — slowlyInsert needle into the peptide vial at an angle so the tip touches the inside glass wall. Inject the BAC water slowly, letting it run down the glass — do not squirt directly onto the powder as this can degrade the peptide.
5. Swirl gently until dissolvedGently roll the vial between your palms or swirl slowly. The powder should dissolve completely within 30–60 seconds. The solution should be clear and colorless (some peptides have a slight color — this is normal; check your COA).
6. Do not shakeShaking can cause peptide degradation. Always swirl or roll gently.
7. Store correctlyRefrigerate at 2–8°C (standard fridge). Keep away from light. Use within 4–6 weeks. Lyophilized (unreconstituted) peptides can be stored frozen for 12–24 months.

Reconstitution Calculator

Storage & Stability

• Lyophilized (freeze-dried) peptide — store at -20°C (freezer) for 12–24+ months; room temperature acceptable for short periods during shipping
• Reconstituted peptide (in BAC water) — refrigerate at 2–8°C; use within 4–6 weeks
• Avoid freeze-thaw cycles of reconstituted peptide — draw out working aliquots if needed for long-term research
• Keep away from light — UV exposure can degrade sensitive peptides
• Do not leave at room temperature — reconstituted peptides degrade faster at ambient temps

Frequently Asked Questions

What if the peptide doesn't fully dissolve?

Most research peptides dissolve readily in BAC water. If dissolution is slow, allow additional time and continue gentle swirling. Some peptides (e.g. certain GHRPs) may benefit from a brief warm water bath (not hot). If the powder still won't dissolve, check whether your specific peptide requires acetic acid solution instead of BAC water.

Can I use sterile saline or plain sterile water?

Plain sterile water contains no preservative and should only be used for single-use reconstitution (use entire vial within 24 hours). Bacteriostatic water's benzyl alcohol content inhibits microbial growth and preserves reconstituted peptide for 4–6 weeks refrigerated. Saline (0.9% NaCl) can also be used but offers no preservation advantage.

What gauge needle should I use?

28–31 gauge needles are standard for peptide work. Finer gauges (30–31G) minimize stopper coring but are suitable for the small volumes involved. Insulin syringes (U-100, 1mL or 0.5mL) are ideal for their precise graduation markings at low volumes.

How do I calculate my dose from a reconstituted vial?

Use the calculator above or the formula: syringe volume (mL) = desired dose (mg) ÷ concentration (mg/mL). Example: 0.3mg dose from a 2mg/mL solution = 0.15mL = 15 units on a U-100 insulin syringe.