How to reconstitute a lyophilized peptide

Reconstituting a lyophilized peptide means slowly adding bacteriostatic water down the side of the vial, then swirling — never shaking — until the powder dissolves. Done gently it takes a couple of minutes and preserves the purity you paid for. Done roughly, you lose some of the molecule before you've even started.

What you need

• The lyophilized vial (the dry powder)
• Bacteriostatic water as the solvent
• A sterile syringe to measure and transfer the water
• An alcohol wipe for the rubber stoppers

Bacteriostatic water is preferred for research handling because its preservative slows microbial growth, so a reconstituted vial stays usable longer than it would with plain sterile water — see bacteriostatic water vs. sterile water for the full comparison.

The technique that protects purity

The goal is to dissolve the powder without battering the molecule.

1. Wipe the stopper on both vials with alcohol.
2. Draw your chosen volume of bacteriostatic water into the syringe.
3. Push the needle through the stopper and aim the stream at the glass wall, not directly onto the powder. Let it trickle down.
4. Swirl gently. Do not shake. If a little powder remains, leave the vial to sit for a few minutes and it will finish dissolving on its own.

A clean reconstituted solution is clear. Cloudiness, floating particles, or powder that refuses to dissolve are signals something is off with the material — worth checking against the vial's lab report.

Working out the concentration

This is just division, and it's the part people overthink.

Concentration = amount of peptide ÷ volume of water added

So the same vial gives you different concentrations depending on how much water you use:

The amount of peptide in the vial never changes — only the concentration does. Pick a water volume that lands you on a number that's easy to measure for your protocol.

Mistakes that quietly cost you

• Shaking — foam and shear forces degrade the peptide. Swirl instead.
• Blasting water straight onto the powder — same problem. Aim at the wall.
• Guessing the starting amount — your concentration math is only as good as the milligram figure on the vial. That figure should be backed by a real report.

That last point is where sourcing matters. Your calculation assumes the vial actually contains what the label claims. Every pepuro vial carries a QR code linking to its own third-party report at pepuro.com/v/<uuid>, so the milligram amount and purity you're doing math against are verified for that specific vial, not assumed. (If you're not sure how to read that report, see how to read a peptide lab report.)

Quick recap

• Use bacteriostatic water.
• Run it down the glass, swirl, never shake.
• Concentration = peptide ÷ water volume.
• Trust your math only as far as you trust the vial's report.

Every peptide in our catalog ships lyophilized and ready to reconstitute this way.

For research use only. Not for human or animal consumption.