Semaglutide Reconstitution Calculator
Works out your Semaglutide dose from what labs actually weighed in the vial, not just the label. Across 9 lab-weighed Semaglutide vials, the median held 11% more than its label, and 56% were more than 10% over.
Have the vial? Enter its batch identifier to use its lab-tested exact weight.
Draw
20 units
on a U-100 insulin syringe, for 1 mg — if the vial holds exactly what the label says
Labels are rarely exact. Across 9 lab-weighed Semaglutide vials, the median held 11% more than its label — from a vial like that, 20 units is about 1.11 mg. Look up your lot number for its exact weight.
- The vial holds dry powder: 10 mg of Semaglutide, as labelled.
- Water spreads that powder evenly through the liquid: 10 mg ÷ 2 ml = 5 mg per ml.
- An insulin syringe counts in units, 100 to the ml, so each unit carries 50 mcg.
- Your dose divided by that: 1 mg ÷ 50 mcg = 20 units.
The water changes how many units a dose takes, never how much peptide you get. Twice the water means twice the units for the same dose. What sets the dose is how much is in the vial — which is why the measured amount matters.
Arithmetic, not medical advice. Assumes a U-100 syringe and that the powder fully dissolves.
Recently weighed Semaglutide lots
Open a lot to dose from its exact weight.
All Semaglutide test results by vendor →
How to reconstitute Semaglutide vials
- Wipe the vial top and the bacteriostatic water top with alcohol.
- Draw the water you chose — 1 to 3 ml is usual — and run it slowly down the inside of the vial, not onto the powder.
- Swirl gently until it is clear. Do not shake.
- Work out units per dose with the calculator above, using the amount actually in the vial.
Why the label isn't your dose
Every other calculator divides the number on the label by the water. The label is the amount the vendor aimed for, not the amount in the vial. Across 9 Semaglutide vials weighed by labs, the median held 11% more than its label — so a dose drawn by the label is usually larger than you meant it to be.
PepBatch reads the lab reports for each lot. Enter your lot number and the calculator uses the weight the lab measured for your batch instead of the label.
Units, ml and mg on an insulin syringe
A U-100 insulin syringe is marked in units: 100 units is 1 ml, so 10 units is 0.1 ml. A unit is a volume, not a dose. How much peptide a unit carries depends on how much powder is in the vial and how much water you added — which is why the same 10 units can be 250 mcg from one vial and 500 mcg from another.
More water makes each unit weaker, so a dose takes more units. That is useful for small doses, which are hard to measure under about 5 units. It never changes how much peptide a dose contains.
Arithmetic, not medical advice. Weighings are from completed lab reports on PepBatch; results that found the wrong peptide, blends, and weights that cannot belong to the labelled vial size are left out.