How much bacteriostatic water do I add to a peptide vial?

For a 5 mg vial, adding 1 mL gives 5000 µg/mL and adding 2 mL gives 2500 µg/mL. More BAC water = lower concentration per mL, making small doses easier to measure accurately on a U-100 syringe.

Can I use sterile water instead of bacteriostatic water?

Sterile water is single-use only — once the vial is punctured, it must be discarded. Bacteriostatic water contains 0.9% benzyl alcohol which prevents microbial growth, making multi-draw vials safe for 28 days.

Why should you never shake a peptide vial?

Shaking creates foam and mechanical stress that can break disulfide bonds and denature the peptide. Always swirl gently or let the vial sit and dissolve naturally.

Reconstitution Guide

How to Reconstitute Peptides: Step-by-Step

Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder into a liquid for injection. Done wrong, it can degrade your compound before a single dose is used.

TL;DR — Swab the vial, draw BAC water slowly, inject it down the vial wall, swirl gently, then refrigerate. Never shake. Use the ASCEND calculator to determine exact draw volumes.

What You Need

Supplies

Peptide VialLyophilized powder

BAC WaterBacteriostatic water

U-100 SyringeInsulin syringe

Alcohol Swabs70% isopropyl

The Process

7 Steps to Reconstitute Safely

Wash your hands

Use soap and water for 20 seconds before handling vials or syringes.

Swab both vial stoppers

Wipe the rubber stopper of the peptide vial and the BAC water vial with an alcohol swab. Let air-dry for 10 seconds.

Draw your BAC water

Insert the syringe into the BAC water vial and pull back the plunger to draw the volume you need (typically 1–2 mL for a 5 mg peptide vial).

Insert needle into peptide vial at an angle

Tilt the peptide vial slightly. Insert the needle through the stopper so the tip points toward the glass wall, not the powder.

Press plunger slowly — down the wall

Release the BAC water in a slow, steady stream against the inside glass wall. The liquid should run down and pool at the bottom. This prevents foaming and mechanical stress on the peptide.

Swirl gently — never shake

Roll the vial between your palms or swirl in a slow circle until the powder fully dissolves. The solution should be clear. If cloudy, let it sit for 5 more minutes at room temperature.

Label and refrigerate

Write the date and concentration on the vial label. Refrigerate at 2–8°C. Most reconstituted peptides remain stable for 4–6 weeks.

Never shake the vial. Shaking creates bubbles and mechanical agitation that can disrupt the peptide's structure. Swirling is always sufficient.

The Math

Calculating Your Concentration

Once you've added your BAC water, your concentration is simple:

Formula

µg/mL = Vial Amount (µg) ÷ BAC Water Added (mL)

Example: 5 mg vial (5000 µg) + 2 mL BAC water = 2500 µg/mL

Tip: Use more BAC water to lower the concentration — this makes small doses (like 250 µg) much easier to measure accurately on a U-100 syringe. ASCEND calculates your exact draw volume automatically.

FAQ

Common Questions

How much BAC water do I add?

For a 5 mg vial: 1 mL gives 5000 µg/mL; 2 mL gives 2500 µg/mL. Use the ASCEND calculator — enter your vial size and desired dose and it shows the exact BAC water volume and draw IU.

Can I use sterile water instead of BAC water?

Sterile water is single-use. Once punctured, it should be discarded. BAC water contains 0.9% benzyl alcohol which prevents microbial growth, making it safe to draw from multiple times over 28 days.

Why is the solution cloudy?

Some peptides dissolve slowly. Let the vial sit at room temperature for 5–10 minutes after swirling. If still cloudy, the peptide may have been degraded or was not properly lyophilized. A fully dissolved peptide solution is clear.

How long does a reconstituted peptide last?

Most reconstituted peptides are stable for 4–6 weeks when refrigerated at 2–8°C and protected from light. Avoid repeated freeze-thaw cycles. Lyophilized (unreconstituted) peptides can last 1–2 years at -20°C.

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