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Reference

Reconstitution, storage, and the practical questions peptide research raises.

A working reference for the compounds we supply. New to the field? Start with the primer.

/01

The method.

Reconstitution is the process of returning a freeze-dried peptide to liquid form. Done well, the peptide retains its structure and remains usable for the weeks ahead. Done carelessly, the molecule can be damaged in the moment it dissolves. The difference is a few minutes of patience and a careful hand.

The method below works for every lyophilised peptide we supply.

One

Let the vial come to room temperature.

Peptides arrive cold and should not be reconstituted cold. A vial taken straight from a cool shipment, or from the fridge after storage, needs ten minutes on the counter before anything else happens. The temperature differential between cold glass and room-temperature water creates condensation inside the vial and can shock the lyophilised cake. Patience here costs nothing and protects everything.
Two

Draw bacteriostatic water into a clean syringe.

The volume depends on the concentration you want to work with. The calculator below works this out from three numbers: how much peptide is in the vial, how much water you intend to add, and the dose you’re working in reference to. Use a fresh sterile syringe each time.
Three

Add the water slowly, against the side of the glass.

Tilt the vial. Rest the needle against the inside wall of the glass at the top of the vial. Depress the plunger slowly so the water trickles down the inside of the glass rather than landing on the powder. Aiming directly at the lyophilised cake disturbs its structure and forces dissolution to happen too quickly.
Four

Roll the vial gently between your palms.

Continue until the powder has fully dissolved. The solution should be clear within a minute or two. Do not shake the vial. Shaking, and any other form of vigorous agitation, damages the peptide. The molecule is held together by bonds that don’t survive being thrown around in solution.
Five

Check the result.

The reconstituted solution should be clear and free of particulate matter. If anything looks off, cloudy, coloured, or with anything visible suspended in it, stop and contact hello@wearenox.io before going further.
/02 Research reconstitution calculator

The calculator.

Work out your draw in seconds. Enter the vial size, the bacteriostatic water you’ll add, and the dose, everything updates as you type.

/01 Vial size
mg

Total peptide content of the vial, from its label.

/02 Solvent volume
ml

Bacteriostatic water added to the vial.

/03 Reference dose

How much peptide you want per dose.

Draw , units ,
Concentration , mcg/ml
Doses per vial ,
Draw on a 100-unit insulin syringe
Explore dose
/03

Storage.

Peptides supplied lyophilised, that is, freeze-dried under vacuum, are remarkably stable in their dry form. Sealed under nitrogen and kept frozen at -20°C for long-term storage, or refrigerated at 2–8°C for shorter periods, an unopened vial remains usable for many months from the date of manufacture. Light and heat are the two factors that shorten this most. Keep the vial in its box, away from the door of the fridge if you can.

Once reconstituted, the solution is more delicate. Refrigerated at 2°C to 8°C, kept upright, and protected from light, most reconstituted peptides remain stable for several weeks under normal research conditions. The bacteriostatic water itself is part of the reason this works, the 0.9% benzyl alcohol it contains is a preservative that prevents bacterial growth in the multi-use vial.

Solution that has changed in colour, clarity, or smell since reconstitution should not be used. Discard and start fresh.

A note on freezing. Most reconstituted peptides should not be frozen. Freeze-thaw cycles damage peptide structure in ways that aren’t always visible. If a specific compound benefits from freezing, some do, that information sits with the compound itself, not as a general rule.

/04

About bacteriostatic water.

Bacteriostatic water is the standard solvent for lyophilised peptide reconstitution. It is sterile water for injection containing 0.9% benzyl alcohol as a bacteriostatic preservative, the alcohol prevents bacterial growth in the vial after the seal has been broken and a needle has been introduced.

This is what allows a single vial of reconstituted peptide to be drawn from repeatedly over the course of weeks. Without the preservative, sterile water becomes a hospitable environment for bacteria within hours of being opened. With it, you have a working solution with a meaningful lifespan.

A sealed bottle of bacteriostatic water stored at room temperature, away from direct light, remains usable until the date printed on the label. Once opened, it remains usable for around 28 days under normal conditions, the standard pharmacopoeial figure for benzyl-alcohol-preserved water.

We supply bacteriostatic water alongside the peptide catalogue. Most lyophilised peptides will reconstitute in 1 to 2 ml per vial, so a 10 ml bottle covers several reconstitutions.

/05

Glossary.

Lyophilisation
Freeze-drying under vacuum. The peptide is frozen, then the surrounding water is removed by sublimation, turning directly from ice to vapour without melting. The peptide survives this process intact and stable because no heat is applied. The dry residue left in the vial is the lyophilised cake.
Reconstitution
The process of returning a lyophilised peptide to solution by adding a suitable solvent, for most peptides, bacteriostatic water.
Bacteriostatic water
Sterile water for injection containing 0.9% benzyl alcohol as a preservative. The standard reconstitution solvent.
Concentration
The amount of peptide dissolved in a given volume of solvent. Expressed as micrograms per millilitre (mcg/ml) or milligrams per millilitre (mg/ml). The same 5 mg vial reconstituted in 1 ml of water gives a more concentrated solution than the same vial reconstituted in 2 ml.
Reference dose
A defined quantity of peptide, used in research protocols and as a comparison point. Stated in micrograms (mcg). The reference dose is independent of the concentration of the solution, different concentrations require different volumes to deliver the same reference dose.
Insulin syringe
A small-volume syringe calibrated to 100 units per millilitre. The fine gradations and small total volume make it the standard tool for measuring small reconstituted-peptide volumes.
Lyophilised cake
The solid form of peptide remaining in the vial after freeze-drying. May look like a compact disc, a small mass at the bottom of the vial, or a fine powder coating the inside, all are normal.
Sealed under nitrogen
Manufactured by replacing the air inside the vial with inert nitrogen gas before sealing. Removes the oxygen that would otherwise slowly oxidise the peptide over time.

This page is provided for laboratory reference and theoretical dilution calculation. It is not dosing guidance, medical advice, or a recommendation for human or animal use. The values shown are mathematical conversions only. All compounds supplied by NOX are intended for in-vitro research and analytical reference. See our Research-Use-Only Agreement for the full position.