Peptide Reconstitution Guide & Dosing Calculator

What Reconstitution Means

Research peptides arrive as a freeze-dried powder. Before you can measure them in a lab, you have to mix them with a liquid. The most common liquid is bacteriostatic water — sterile water with a small amount of benzyl alcohol that helps keep bacteria from growing while it sits in the fridge.

Materials Checklist

• Peptide vial (freeze-dried powder)
• Bacteriostatic water (sterile water with 0.9% benzyl alcohol)
• Mixing syringe (1–3 mL)
• U-100 insulin syringe for measuring doses
• Alcohol wipes
• Sharps container for safe disposal

Step-by-Step Mixing Guide

1. 1. Clean your workspace. Wipe down surfaces and wash your hands. Clean the rubber tops of both vials with alcohol wipes and let them air dry.
2. 2. Draw the water. Using a clean mixing syringe, pull up the amount of bacteriostatic water you planned. More water makes the solution weaker. Less water makes it stronger.
3. 3. Inject slowly down the side of the vial. Aim the water at the glass wall so it runs down, not straight onto the powder. This reduces foam and helps keep the peptide stable.
4. 4. Do not shake. Gently swirl or roll the vial in your hands until the powder fully dissolves. Shaking can damage the peptide structure.
5. 5. Check the liquid. A properly mixed peptide should look clear and colorless, with no bits floating in it. If it looks cloudy or has particles, something may have gone wrong.
6. 6. Store in the fridge. Keep the mixed vial at 2–8 °C (36–46 °F) and away from light. Write the date and the dose strength on the label.

The Basic Math: mg, mcg, mL, and Syringe Units

Two conversions do most of the work:

• 1 mg equals 1,000 micrograms. Vials are usually labeled in mg; small doses are usually measured in mcg.
• 1 mL = 100 units on a standard U-100 insulin syringe. So each unit mark equals 0.01 mL.

Interactive Dosing Calculator

Pick your vial size, how much water you will add, and your target dose. The calculator shows how strong the mix is and how many units to draw. For lab reference only.

Worked Example

Say you mix a 10 mg vial with 2 mL of water. Start with the 10 mg in the vial. Divide by 2 mL and you get 5 mg per mL. A U-100 insulin syringe has 100 units per mL, so each unit is 50 mcg. To get 250 mcg, draw 5 units, which is 0.05 mL.

IU vs mcg — What Is the Difference?

Some products list strength in IU, which stands for International Units. IU is not a weight — it measures activity. The number of mcg in one IU is different for each product. Check the product's certificate of analysis for the exact ratio before converting.

Storage & Stability

• • Unmixed powder: keep in the fridge at 2–8 °C, or in the freezer at −20 °C for long-term storage. Keep away from light and moisture.
• • Mixed solution: keep in the fridge at 2–8 °C. Most last about 28 days after mixing. Check the product's own data for exact shelf life.
• • Do not freeze and thaw mixed solution over and over. Repeated temperature changes can break down the peptide.

Common Mixing Mistakes

• • Shaking the vial instead of gently swirling — this can damage the peptide.
• • Shooting water straight onto the powder cake, which creates foam.
• • Mixing up mg and mcg during the math — always convert mg to mcg first.
• • Forgetting that a U-100 syringe reads in units, not mL — 100 units = 1 mL.
• • Leaving mixed peptides at room temperature or in direct light.