⚠ Please read
This peptide calculator helps you reconstitute your peptide correctly: it shows
how much water to add to the vial and exactly how many units to draw on an
insulin syringe. It handles the mixing math only — your dose, schedule, and whether a
peptide is right for you are decisions for your clinician.
1 · Choose your peptide
mg
2 · Desired dose
3 · How much water to add
Water-volume guide for a standard 3 mL vial — choose by how many doses it holds. Other vial sizes may need a different amount.
1–2 doses0.5 mL
3–6 doses1 mL
7–14 doses2 mL
15+ doses3 mL
mL
Result — amount to draw
— mL
= — on a U-100 insulin syringe
This calculator is provided by Transcend Clinic for the convenience of its patients and is for informational purposes only. It does not constitute medical advice. Always follow the specific instructions provided by your clinician. Verify all doses before administration. If you are unsure, contact the clinic.
How to use this calculator
- Choose your peptide (or enter the total amount in the vial in mg).
- Enter your dose per injection — switch between mg and mcg as needed.
- Pick how much water to add. The calculator suggests a sensible volume based on how many doses are in the vial; you can override it.
- Read your result. You'll get the exact volume to draw in millilitres, the equivalent in insulin-syringe units, and the nearest unit mark to draw to.
What "reconstitution" means
Most peptides are supplied as a freeze-dried (lyophilised) powder that has to be dissolved before use. Reconstitution simply means adding a measured amount of water — either sterile water or bacteriostatic water — to turn that powder into an injectable solution. How much water you add doesn't change the total amount of peptide in the vial; it only changes the concentration, and therefore how many units you draw for a given dose. More water makes each dose a slightly larger, easier-to-measure volume; less water makes it more concentrated.
Reading your dose on an insulin syringe
The calculator gives your dose in units on a standard U-100 insulin syringe, where 100 units = 1 mL (so 1 unit = 0.01 mL). Because syringes are only marked to the nearest unit or two, we round to the closest line and tell you which mark to draw to. If your result lands between marks, draw to the nearest one — the small difference is not clinically significant for most peptides, but check with the clinic if you're unsure.
Which water to use, and storage
You can reconstitute with either sterile water or bacteriostatic water. Bacteriostatic water contains a small amount of preservative (benzyl alcohol) that helps limit bacterial growth; sterile water has none. Either one can be used to mix a vial you'll draw from over several doses — the important part with both is clean, careful handling: keep the vial refrigerated, wipe the rubber stopper with alcohol before each draw, protect it from light, and avoid vigorous shaking. Use it within the timeframe your clinician advises, as this varies by peptide.
Frequently asked questions
Does this peptide calculator tell me my dose?
No. It only calculates reconstitution — how to mix the vial and how much to draw for a dose you've already been given. Your dose, frequency, and course of treatment should be set by your doctor or clinician.
How much water should I add to the vial?
There's no single "correct" amount — it's a trade-off. The calculator suggests a volume based on how many doses are in the vial, which keeps each injection an easy-to-measure size. You can add more or less depending on your preference.
Sterile water or bacteriostatic water — which should I use?
Either works for reconstitution. Bacteriostatic water contains a preservative (benzyl alcohol); sterile water does not. Both can be used across several doses when the vial is kept refrigerated and handled cleanly. Sterile water is a good choice if benzyl alcohol needs to be avoided.
Why does the result show "units" instead of millilitres?
Because most people inject peptides with an insulin syringe, which is marked in units, not millilitres. We show both so you can measure accurately whichever way your syringe is marked.
How long does a peptide last once it's mixed?
It depends on the specific peptide, but reconstituted peptides are typically kept refrigerated and used within the timeframe your clinician advises. Check your peptide's guidance or ask the clinic.
Can I use this for any peptide?
The mixing math is the same for any vial, so yes — but whether a particular peptide is appropriate for you, and at what dose, is a clinical decision.
Talk to the clinic
Not sure about your peptide protocol? The Transcend Clinic team can review your peptide, dose, and goals and make sure you're reconstituting and injecting correctly.
Book a consultation