Semaglutide Calculator

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

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 .

Semaglutide is a synthetic analog of glucagon-like peptide-1 (GLP-1), an incretin hormone secreted by intestinal L-cells in response to nutrient intake. The molecule binds the GLP-1 receptor and has been studied extensively in published research for its effects on glucose-dependent insulin secretion, gastric emptying, and central appetite signaling. Structural modifications — notably a fatty acid side chain that reversibly binds albumin — extend its plasma half-life substantially compared to native GLP-1. Semaglutide has been the subject of large clinical trials reported in journals including the New England Journal of Medicine, and has been approved by regulatory agencies under brand names including Ozempic, Rybelsus, and Wegovy for use by prescription. Research-grade semaglutide sold by chemical supply companies is labeled for laboratory use only and is not approved by the FDA for human consumption in that form.

See all GLP-1 peptides →

How to reconstitute Semaglutide

Research chemical vendors typically offer semaglutide in lyophilized vials of 2 mg, 3 mg, 5 mg, and 10 mg. A 5 mg vial reconstituted with 1 mL of bacteriostatic water yields a 5,000 mcg/mL solution.

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

Most Semaglutide draw errors are unit errors, not arithmetic errors: confusing mg with mcg (1 mg = 1,000 mcg), or reading a U-40 syringe with U-100 math — the same printed mark holds 2.5× the volume. Two more worth avoiding: leaving the vial unlabeled, so the concentration and reconstitution date are lost, and under-diluting to the point where the draw is under about one unit and can no longer be read accurately.

Each of these is covered in full in the guides: reconstitution math from first principles, U-100 vs U-40 syringes, storage and shelf life, and how to reconstitute peptides.