Your first time with peptides
Reconstituting and dosing a peptide for the first time can feel overwhelming. This guide walks through the whole process, from supplies to math to hygiene, so you can use the calculator with confidence.
This guide is for laboratory research only. It is not medical advice.
What you need
Gather everything before you start. Never improvise mid-procedure.
Peptide vial
Lyophilized (freeze-dried) peptide powder, stored per its label, usually refrigerated.
Solvent
Bacteriostatic water for multi-dose vials; sterile water for single use.
Syringes & needles
U-100 insulin syringes for measuring; a larger needle for reconstitution.
Alcohol swabs
To wipe vial stoppers and your work surface before every step.
Sharps container
A puncture-proof container for used needles. Never recap by hand.
Reconstitution, step by step
Prep your space
Wash your hands, clean the work surface with an alcohol swab, and lay out every supply within reach.
Wipe the vial stopper
Swab the rubber stopper of the peptide vial and the solvent vial, then let them air-dry for a few seconds.
Draw the solvent
Using the reconstitution needle, draw the solvent volume you plan to add, then tap and push gently to remove air bubbles.
Add solvent slowly
Inject the solvent down the inside wall of the peptide vial, not directly onto the powder. This prevents foaming.
Gently swirl
Roll or swirl the vial gently until the powder fully dissolves. Never shake, because shaking can damage peptides.
Label & store
Write the date, concentration (mg/mL), and peptide name on the vial, then refrigerate unless the label says otherwise.
Understanding the numbers
Three units matter: mg (mass), mL (volume), and units (syringe marks). Here is how they connect.
mg and mcg
1 mg = 1000 mcg. A 5 mg vial holds 5000 mcg of peptide. Doses are usually written in mcg, for example 250 mcg.
mL and units
On a U-100 insulin syringe, 100 units = 1 mL. If 2 mL of solvent is added, the full syringe holds 200 units.
Concentration
Concentration = peptide (mg) divided by solvent (mL). A 5 mg vial with 2 mL gives 2.5 mg/mL, a common and easy ratio.
Worked example
5 mg vial + 2 mL solvent = 2.5 mg/mL = 25 mcg per unit (100 units/mL). A 250 mcg dose = 10 units. The calculator does this for you, but understanding it means you can sanity-check any result.
Hygiene & safety
The rules that keep research protocols clean and reproducible.
- Always use a fresh needle and syringe for every draw. Never reuse.
- Never touch the needle or the vial stopper after wiping.
- Keep peptides refrigerated and away from direct light after reconstitution.
- Discard any vial that looks cloudy, discolored, or has unexpected particles.
- Dispose of sharps in a proper container and never recap needles by hand.
Common mistakes to avoid
Shaking the vial
Vigorous shaking can denature delicate peptides. Always swirl gently.
Mixing up units
Reading 25 mg as 25 mcg, or drawing 100 units when you need 10, is a classic error. Use the calculator, then double-check.
Skipping hygiene steps
Skipping an alcohol wipe or reusing a needle compromises the whole batch.
Forgetting the label
An unlabeled vial becomes a guessing game later. Always write the date and concentration.
Ready to calculate your dose?
Open the reconstitution calculator and see your exact draw, with the syringe and pen visuals.