Semaglutide dose steps are small — a starting dose is a fraction of a millilitre at most concentrations — which makes the reconstitution arithmetic matter more here than almost anywhere else. This runs the whole chain with the labelled dose steps built in.
Reconstitution calculator
Enter the vial as labelled and the bacteriostatic water you actually added. Nothing is stored or sent anywhere.
Semaglutide dose steps are small — a 0.25 mg starting dose is a fraction of a millilitre at most concentrations.
How to Use This Calculator
The vial, the water, your step, your syringe.
Enter the vial strengthThe milligram figure on the vial before reconstitution — commonly 2 mg, 5 mg or 10 mg.
Enter the bacteriostatic water you addedIn mL. Record it against the vial; it is the number the rest of the math hangs on.
Pick your dose stepThe labelled semaglutide ladders run 0.25, 0.5, 1, 1.7 and 2.4 mg depending on the product. Or type a custom amount.
Match your syringeCheck the barrel rating. U-100 and U-40 syringes read identical volumes differently.
How the Math Works
Four steps, all plain arithmetic.
Concentration. Vial strength divided by the volume of bacteriostatic water you added, in mg/mL. Every number below depends on this one, and it changes if you reconstitute the next vial differently. Standard reconstitution arithmetic.
Draw volume. Your dose divided by the concentration, in mL.
Syringe reading. Draw volume multiplied by the syringe's units-per-mL rating. A U-100 and a U-40 syringe give different readings for an identical volume — check what is printed on the barrel. ISO 7864 syringe graduation standards.
Doses per vial. Vial strength divided by your dose step. This falls as you move up the ladder, which is also why cost per dose rises. See the Cost Planner.
Why small doses need more care
The specific risk with semaglutide rather than generic advice.
A 0.25 mg step is a very small volume. From a 5 mg vial in 2 mL, that is 0.1 mL — ten units on a U-100 syringe. Misreading by two units is a 20% error on the dose. Choosing a diluent volume that puts your draw in a comfortably readable range is worth doing deliberately.
Two different ladders exist. Semaglutide products run to a maximum of either 2 mg or 2.4 mg weekly depending on the product and indication. The steps here cover both; which applies to you is your prescriber's call. See the Titration Planner.
Arithmetic only — not medical advice. This calculator divides numbers you enter. It does not recommend a dose, a diluent volume, a syringe, or a product, and it cannot verify what is actually in your vial. The dose steps offered as presets are the manufacturers' published labelled schedules, included for convenience — your prescriber sets your actual schedule. Peptide Plug does not sell, supply or source any compound.
Frequently Asked Questions
How much bacteriostatic water should I use for semaglutide?
That is a decision for you and your prescriber or pharmacist. The calculator works with whatever volume you actually added. As a practical matter, a volume that puts your draw in a comfortably readable range on your syringe is easier to reproduce accurately week to week.
What are the labelled semaglutide dose steps?
Depending on the product, ladders run 0.25 → 0.5 → 1 mg with a maximum of 2 mg weekly, or 0.25 → 0.5 → 1 → 1.7 → 2.4 mg weekly. Both sets are offered here as presets. Which applies to you is your prescriber's decision.
Why does a small dose need more diluent, not less?
More diluent lowers the concentration, so the same dose becomes a larger volume — and a larger volume is easier to measure accurately on a syringe. The dose is unchanged; only the readability improves.
Is compounded semaglutide the same as the approved product?
No. Compounded and research-grade semaglutide is not the approved product, and that distinction matters. Our semaglutide reference page covers the regulatory position.
How many doses are in my vial?
Vial strength divided by your dose step, shown above. Expect slightly fewer in practice because of residual volume, drawing waste and the discard window.
Does the syringe type really change the dose?
It changes the number you read, not the volume you draw. But if you read a U-40 syringe as though it were U-100 you will draw the wrong volume, and the error is more than double.
Does Peptide Plug sell semaglutide?
No. We do not sell, supply, source or link to vendors for any compound. Peptide Plug is a tracking and calculation tool only.