Skip to main content
CalculatePeptide
GLP-1 receptor agonist

Semaglutide Calculator

Dosage and reconstitution math for Semaglutide. A GLP-1 receptor agonist that mimics the GLP-1 incretin hormone and binds to GLP-1 receptors in pancreatic and neural tissue.

Reconstitution calculator

Pre-filled with common defaults for Semaglutide. Adjust any field to match your own vial.

mg
mL
Draw to
units on the syringe
Equivalent volume: mL
Concentration
mcg / mL
Per syringe unit
mcg / unit
Show the math

Enter values above to see the step-by-step math.

Preview of the illustrated reconstitution guide
Free download

Free Illustrated Reconstitution Guide (PDF)

8-step visual walkthrough with photos and tips — from gathering supplies to drawing your dose. Educational only — not medical advice.

Semaglutide reconstitution diagram Semaglutide: 5 mg vial mixed with 2 mL bacteriostatic water yields 2.5 mg/mL. A 250 mcg dose draws to 10 units on a U-100 syringe. 1 Reconstitute 5 mg vial + 2 mL BAC water 2 Calculate concentration 2.5 mg/mL 5 mg ÷ 2 mL = 2.5 concentration 3 Convert dose to volume 250 mcg dose 250 mcg ÷ 2500 mcg/mL = 0.1 mL 4 Draw to mark 0 25 50 75 100 10 units U-100 5 mg vial · 2 mL water · 2.5 mg/mL · 250 mcg dose → 0.1 mL → 10 units on U-100

Semaglutide dosage calculator

The Semaglutide dosage calculator above converts a target dose into exact syringe units based on your vial size and how much bacteriostatic water you used to reconstitute it. Semaglutide is commonly sold in 2 mg, 3 mg, 5 mg, 10 mg vials. The calculator supports both U-100 and U-40 insulin syringes and flags draws that are too large for the syringe barrel or too small to measure accurately. A GLP-1 receptor agonist that mimics the GLP-1 incretin hormone and binds to GLP-1 receptors in pancreatic and neural tissue. Enter your target dose in the calculator above to see the exact number of units to draw.

Semaglutide dosage chart

Sample doseConcentrationVolume to drawUnits on U-100
100 mcg2.5 mg/mL0.04 mL4
200 mcg2.5 mg/mL0.08 mL8
400 mcg2.5 mg/mL0.16 mL16
800 mcg2.5 mg/mL0.32 mL32
1600 mcg2.5 mg/mL0.64 mL64

Semaglutide and GLP-1 peptides

Semaglutide is a GLP-1 receptor agonist. A GLP-1 receptor agonist that mimics the GLP-1 incretin hormone and binds to GLP-1 receptors in pancreatic and neural tissue. The same molecule is the active ingredient in Ozempic and Wegovy and Rybelsus, which are FDA-approved prescription medications manufactured by their respective companies. Research-use Semaglutide is regulated differently and is not approved for human consumption. Other peptides in the GLP-1 class include Tirzepatide , and Retatrutide .

See all GLP-1 peptides →

How to reconstitute Semaglutide

Reconstituting Semaglutide is the same unit-conversion process used for any lyophilized peptide:

  1. Draw your chosen volume of bacteriostatic water into a syringe.
  2. Inject the bacteriostatic water slowly down the side of the Semaglutide vial — do not shoot it directly onto the powder.
  3. Swirl gently until the powder fully dissolves. Do not shake.
  4. Store the reconstituted vial refrigerated.
  5. To dose, calculate your draw volume: divide your target dose by the concentration (vial mg ÷ water mL = mg/mL). The calculator above does this automatically.

For Semaglutide specifically, 2 mg, 3 mg, 5 mg, 10 mg vials are common. A typical reconstitution adds 2 mL of bacteriostatic water, producing a concentration of 2.5 mg/mL for the 5 mg vial size.

Semaglutide half-life and storage

Published pharmacokinetic studies report a terminal half-life of approximately 7 days in humans, reflecting albumin binding and slow receptor-mediated clearance.

Lyophilized semaglutide is typically stored refrigerated at 2–8 °C and protected from light. Reconstituted solutions are generally reported in manufacturer literature to remain stable for several weeks under refrigeration, with exact figures varying by buffer and vial conditions.

Common Semaglutide dosing mistakes

  • Confusing mg and mcg. 1 mg = 1,000 mcg. Always convert to the same unit before computing the draw.
  • Using a U-40 syringe with U-100 math. Same printed mark, 2.5× the physical volume. Always check the syringe label.
  • Not labeling the vial. Write the reconstitution date and concentration on the vial the moment you mix it.
  • Under-diluting. If your draw is less than about 1 unit, the volume is too small to read accurately — add more bacteriostatic water next time.

Semaglutide FAQ

What is Semaglutide? +
Semaglutide is a GLP-1 receptor agonist. A GLP-1 receptor agonist that mimics the GLP-1 incretin hormone and binds to GLP-1 receptors in pancreatic and neural tissue.
How do I calculate my Semaglutide dose? +
Use the calculator above. Enter your vial size (2 mg, 3 mg, 5 mg, 10 mg are common for Semaglutide), the amount of bacteriostatic water you added, and your target dose. The calculator returns the exact number of syringe units to draw.
What vial sizes does Semaglutide come in? +
Semaglutide is commonly available in 2 mg, 3 mg, 5 mg, 10 mg vials.
How long does Semaglutide last? +
Semaglutide's reported half-life is ~7 days.
How should I store Semaglutide? +
Lyophilized semaglutide is typically stored refrigerated at 2–8 °C and protected from light. Reconstituted solutions are generally reported in manufacturer literature to remain stable for several weeks under refrigeration, with exact figures varying by buffer and vial conditions.
What is the difference between Semaglutide and Ozempic? +
Semaglutide is the active ingredient in Ozempic. The molecule is the same. Ozempic is an FDA-approved prescription product manufactured by its maker; research-use Semaglutide is sold under different regulations and is not approved for human consumption.