Tools · Visual Guide

How to Reconstitute Peptides

A step-by-step, interactive walkthrough of turning a freeze-dried vial into a measurable solution, with two fully worked examples.

Peptide vial, bacteriostatic water, insulin syringe and alcohol pads laid out on a clean surface — What you'll typically see in published procedures: lyophilised peptide vial, bacteriostatic water, insulin syringe and alcohol pads.

Worked examples

Pick a vial size

Concentration

10 mg/mL

10000 mcg/mL

Target: 1 mg

Step 1
Concentration
20 mg ÷ 2 mL
= 10 mg/mL
Step 2
Volume for 1 mg
1 mg ÷ 10 mg/mL
= 0.1 mL
Step 3
Syringe units
0.1 mL × 100
= 10 units
Step 4
Aliquots per vial
20 mg ÷ 1 mg
= 20

The 20 mg vial is twice as concentrated, so the same 1 mg sits in half the volume: 10 units. Small volumes are harder to measure precisely; some procedures add more water to make marks easier to read.

Vial	Water	Concentration	1 mg =	Units	Aliquots
20 mg	2 mL	10 mg/mL	0.1 mL	10	20
10 mg	2 mL	5 mg/mL	0.2 mL	20	10

The process

Five steps, one at a time

1. Prepare

Let both vials reach room temperature. Wash hands, then wipe each rubber stopper with a fresh alcohol pad and let it air dry.

Storage notes commonly cited

Unmixed powder: cool, dry, away from light; refrigerate or freeze for longer storage.
Once reconstituted: refrigerate (2–8 °C) and keep from light.
Discard if cloudy, discoloured or containing particles.
Use a fresh sterile needle every time the stopper is pierced.

Try your own numbers

Use the calculator for any vial size, water volume or target amount, in mg or mcg.

Open the calculator

This guide explains arithmetic and general laboratory handling for educational purposes. The 1 mg figure is an example for the maths only, not a recommended amount for any person. It is not medical advice; many of these compounds are not approved for human use.