Semaglutide Dosage Calculator & Units Chart
Branded Wegovy and Ozempic pens are dosed in milligrams and pre-set, so there's nothing to measure. Compounded semaglutide comes in multi-dose vials, and you have to turn your mg dose into units on an insulin syringe yourself. Enter your vial's concentration to get the exact draw, and see every step of the dose schedule in units.
Used only to count doses per vial.
= 0.1 mL of a 2.5 mg/mL solution, delivering 0.25 mg (250 mcg).
Semaglutide dose steps at 2.5 mg/mL
Every dose your prescriber may move you through, converted for your vial. Follow your own prescription.
| Dose | mL | Units (U-100) | Typical use |
|---|---|---|---|
| 0.25 mg | 0.1 | 10 | Weeks 1–4 (starting dose) |
| 0.5 mg | 0.2 | 20 | Weeks 5–8 |
| 1 mg | 0.4 | 40 | Weeks 9–12 |
| 1.7 mg | 0.68 | 68 | Weeks 13–16 |
| 2.4 mg | 0.96 | 96 | Week 17+ (Wegovy maintenance) |
Semaglutide dosing chart in units
Units on a U-100 insulin syringe for each labeled dose, at three common compounded concentrations. If your vial uses a different strength, use the calculator.
| Dose | 1 mg/mL | 2.5 mg/mL | 5 mg/mL |
|---|---|---|---|
| 0.25 mg | 25 units | 10 units | 5 units |
| 0.5 mg | 50 units | 20 units | 10 units |
| 1 mg | 100 units | 40 units | 20 units |
| 1.7 mg | 170 units | 68 units | 34 units |
| 2.4 mg | 240 units | 96 units | 48 units |
At 1 mg/mL, the higher doses go past 100 units and won't fit in a standard 1 mL syringe. At 5 mg/mL, the starting dose is just 5 units, so a 0.3 mL syringe with half-unit marks makes it much easier to measure accurately.
The 5-units-vs-50-units mistake
In July 2024 the FDA issued an alert about compounded semaglutide overdoses. In the cases it described, patients told to draw 5 units (0.05 mL) drew 50 units (0.5 mL) instead, and some prescribers converted milligrams to units incorrectly. People ended up taking five to twenty times their intended dose, and some were hospitalized with severe nausea, vomiting and dehydration.
Three habits prevent nearly all of these errors:
- Know your dose in mg and your vial's mg/mL, not just a unit count.
- Work out the units yourself (or with the calculator) and confirm they match the pharmacy's instructions.
- Use the smallest syringe that holds your dose, and redo the math whenever a new vial arrives.
How long a vial lasts
Total mg in the vial ÷ weekly dose = weeks of supply. A 5 mg vial covers 20 weeks at 0.25 mg, 10 weeks at 0.5 mg and about 2 weeks at 2.4 mg. A vial bought during escalation often spans a dose increase, so the calculator's “vial lasts” figure is for your current dose only. Compounded vials also carry a beyond-use date, which can come first.
Frequently Asked Questions
How many units is 0.25 mg of semaglutide?
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At 2.5 mg/mL, 0.25 mg is 0.1 mL, or 10 units on a U-100 insulin syringe. At 5 mg/mL it is 5 units, and at 1 mg/mL it is 25 units. The answer always depends on the concentration printed on your vial.
How many units is 0.5 mg of semaglutide?
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At 2.5 mg/mL, 0.5 mg is 20 units (0.2 mL). At 5 mg/mL, it is 10 units (0.1 mL).
How many units is 1 mg of semaglutide?
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At 2.5 mg/mL, 1 mg is 40 units (0.4 mL). At 5 mg/mL, it is 20 units (0.2 mL).
What is the standard semaglutide dose schedule for weight loss?
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The Wegovy label starts at 0.25 mg once weekly for 4 weeks, then 0.5 mg, 1 mg and 1.7 mg for 4 weeks each, reaching the 2.4 mg maintenance dose at week 17. Ozempic, labeled for type 2 diabetes, follows a similar start but tops out at 2 mg. Prescribers often slow the escalation if side effects are hard to tolerate.
Why are units so different between pharmacies?
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Compounding pharmacies don't use one standard concentration. Common strengths include 2.5 mg/mL and 5 mg/mL, and products combined with B12 or other additives may be weaker. Same dose, different concentration, different units. Recalculate whenever your pharmacy or vial strength changes.
What if I miss a semaglutide dose?
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Under the Wegovy label, if your next scheduled dose is more than 2 days away, take the missed dose as soon as you can. If it's less than 2 days away, skip it and take the next one on schedule. If you miss more than 2 weeks, talk to your prescriber about restarting, since you may need to step back down.
Medical disclaimer: This calculator converts the numbers you enter; it does not choose or change your dose. The schedule shown is the FDA-labeled escalation for Wegovy, and your prescriber may use a different one. Always follow your prescription and your pharmacy's label, and call the pharmacy if your calculated units don't match their instructions. Not medical advice.