How to Reconstitute Your Peptides in Canada: A Step-by-Step Guide

By Judith Wenshuk, peptide research writer

Quick Answer: Reconstituting a peptide means dissolving the freeze-dried (lyophilized) powder in bacteriostatic water so it can be measured and used. The process takes about five minutes, needs only a few basic supplies, and the biggest mistake beginners make is shaking the vial instead of swirling it gently.

Peptides arrive freeze-dried because it’s the most stable form for shipping and storage — lyophilized powder can sit in the fridge for up to two years, while reconstituted (dissolved) peptide only lasts about 30 days before it starts to degrade. Reconstitution is simply the step that turns the stable powder into a usable liquid. Reconstitution works the same way no matter where your peptides come from, but if you’re sourcing from a Canadian supplier, here’s exactly what the process looks like from vial to usable solution.

What You’ll Need

• Your peptide vial (lyophilized)
• Bacteriostatic water
• Alcohol swabs
• An insulin syringe (typically 29–31 gauge)
• A sharps container (recommended, not required)

Step-by-Step

1. Remove the caps from both the peptide vial and the bacteriostatic water vial.
2. Sanitize both rubber stoppers with an alcohol swab and let them air-dry for a few minutes.
3. Draw the bacteriostatic water into your insulin syringe — pull back the plunger to your target volume. If you draw too much, just push the excess back into the vial.
4. Insert the needle into the peptide vial at a slight angle. Insulin syringes use a very fine needle (29–31 gauge), which is exactly what you want here — fine enough to avoid damaging the rubber stopper on repeated use.
5. Release the water slowly, letting it run down the inside wall of the vial rather than injecting it directly into the powder.
6. Swirl — don’t shake. Gently swirl, tilt, and roll the vial for two to five minutes until the powder is fully dissolved. Shaking can damage the peptide structure.
7. Check the solution. It should be clear, with no visible particles. If it looks cloudy, give it another minute of gentle swirling.
8. Cap, label, and store the reconstituted vial in the fridge. It’s good for approximately 30 days from this point.

How Much Bacteriostatic Water Should You Use?

This depends on the vial size and how precisely you want to measure smaller amounts. Smaller vials generally hold up to 3 mL, and most people use around 2 mL of bacteriostatic water for these — anywhere from 1–3 mL works. Using more water makes fine measurement easier but means a larger total volume, which can matter depending on your syringe size.

Calculating Concentration

Once reconstituted, the math for figuring out how much liquid equals a given amount of peptide is simple:

Bacteriostatic water (mL) ÷ Total peptide (mg) = mL per 1 mg

For example: a 5 mg vial reconstituted with 2 mL of bacteriostatic water gives you 0.4 mL per 1 mg. From there, you can scale that number up or down for any amount. Use the calculator below to do this automatically for your own numbers.

Storage After Reconstitution

• Keep reconstituted vials in the fridge whenever they’re not in use
• Avoid room temperature for more than a few hours
• Never freeze a reconstituted vial — freezing and thawing can damage the peptide
• Reconstituted peptide is generally good for about 30 days

Frequently Asked Questions

Can I use regular sterile water instead of bacteriostatic water? Bacteriostatic water contains a small amount of benzyl alcohol, which helps prevent bacterial growth over the vial’s usable life. Plain sterile water doesn’t have this and isn’t designed for multi-use vials.

What if I accidentally shook the vial? It’s not necessarily ruined, but shaking can cause protein/peptide denaturation. Check that the solution still looks clear — if it’s cloudy or has visible clumps, it’s best not to use it.

Can reconstituted peptide be frozen? Not recommended — freezing and thawing can break down the peptide structure.

This process is the same whether you’re working with BPC-157, Retatrutide, or any other compound from a research peptide supplier in Canada.