How to reconstitute peptides

What you need

• The peptide vial (lyophilized powder)
• Bacteriostatic water (0.9% benzyl alcohol, multi-dose)
• A syringe to transfer the water (a 3 mL syringe, or the same U-100 syringe you draw with)
• Alcohol prep pads
• A sharps container for used needles
• A label or marker

Step 1: decide how much water

Pick a water amount that puts your dose between about 10 units and the capacity of your syringe. Use the calculator: it shows the draw for any vial-and-water combination and warns when a draw is too small or too large. Round concentrations (10 mg/mL, 2 mg/mL, 5 mg/mL) make the barrel easiest to read.

Step 2: prep both vials

Let the vials reach room temperature. Flip the caps and wipe both rubber stoppers with a fresh alcohol pad. Let them dry.

Step 3: draw the water

Draw the water in as many pulls as your syringe needs. The calculator's "How to add the water" panel counts them: 2 mL on a 30U syringe is six full draws plus a 20-unit draw. Tap and push out air before each transfer.

Step 4: add the water slowly, down the glass

Insert the needle at an angle and let the water run down the inside wall of the peptide vial, not straight onto the powder. Pressure builds in a small vial; go slowly and let the plunger move on its own where it can.

Step 5: swirl, do not shake

Roll the vial gently between your fingers or swirl until the solution is clear. Shaking foams it. Some compounds take a few minutes; NAD+ can take longer. If particles remain after several minutes, stop and check the product's own guidance.

Step 6: label it

Write the peptide, the mixed-on date, the concentration (mg/mL) and the mcg per unit on the vial. The calculator's summary strip shows exactly those numbers; copy them. A labeled vial is the difference between a 10-unit draw and a 20-unit mistake three weeks later.

Storage after mixing

Once mixed, keep the vial refrigerated and protected from light, and use it within the window the product specifies. Unmixed powder is generally stored cold and dry per the label. Bacteriostatic water is what makes multi-day use possible; sterile water without preservative is single-use.

The arithmetic

Mistakes that waste vials

• Adding more water than the vial can hold (the calculator does not know your vial's capacity)
• Shaking instead of swirling
• Forgetting to label the concentration
• Mixing to a concentration that makes the dose a 2-unit draw
• Using a U-40 syringe with U-100 math

Common questions

How much bacteriostatic water do I add to a peptide?

Enough to make your dose an easy draw, usually 1 to 3 mL for a 5 to 10 mg vial. Use the calculator to see the units for each amount and pick the one that lands between 10 units and your syringe's capacity.

Do you shake peptides after adding water?

No. Swirl or roll the vial gently until clear. Shaking foams the solution.

How long does reconstituted peptide last?

It depends on the compound and how it is stored. Refrigerate after mixing, protect from light, and follow the product's stated window. Bacteriostatic water is what allows multi-dose use.

Can I add water straight onto the powder?

Aim the stream at the glass wall instead. Letting it run down the side dissolves the powder without foaming.