How to Reconstitute Peptides: Step-by-Step Guide with BAC Water

Most research peptides arrive as lyophilized (freeze-dried) powder in sealed vials. Before use, they must be reconstituted (dissolved) in a sterile solution. Proper reconstitution preserves peptide integrity and ensures accurate dosing.

What You Need

• •Lyophilized peptide vial
• •Bacteriostatic water (BAC water) - water with 0.9% benzyl alcohol as preservative
• •Insulin syringes (for precise measurement)
• •Alcohol swabs (for sterilizing vial tops)

Step-by-Step Reconstitution

Step 1: Calculate Your Volume

Decide how much BAC water to add. Common approach:

• •1 mL of BAC water per 5 mg of peptide
• •This makes dosing math simple

Step 2: Sterilize

Wipe the tops of both the peptide vial and BAC water vial with alcohol swabs.

Step 3: Draw the Water

Using an insulin syringe, draw your calculated volume of BAC water.

Step 4: Add Water Slowly

Critical: Inject the BAC water slowly along the inside wall of the vial. Never squirt it directly onto the peptide powder - this can damage the peptide structure.

Step 5: Let It Dissolve

Allow the water to run down the wall and pool at the bottom. The peptide will begin dissolving on its own. If needed, gently swirl (never shake) the vial.

Step 6: Verify

The solution should be clear. If it's cloudy or has particles, something may have gone wrong.

Storage Guidelines

For complete storage details, see our peptide storage and handling guide.

• •Store reconstituted peptides at 2-8°C (refrigerator)
• •Use within 4-6 weeks after reconstitution
• •Never freeze reconstituted peptides
• •Protect from light and heat
• •Unreconstituted peptides can be stored frozen for months

Dosing Calculation

If you added 1 mL (100 units on insulin syringe) to 5 mg:

• •Each unit = 50 mcg
• •10 units = 500 mcg
• •4 units = 200 mcg

Peptidrop's protocol generator includes dosing calculations in every generated protocol to simplify the math for researchers. For dosing ranges by peptide, see our peptide dosing guide.

For pharmaceutical compounding standards and reconstitution best practices, refer to the United States Pharmacopeia (USP) guidelines.