Last updated: June 2026 · Reviewed June 2026 · Built by the InjectBuddy team
How does semaglutide dosing work? Titration calendar and draw-volume maths
Semaglutide is titrated weekly from a 0.25 mg starting dose up to a 2.4 mg maintenance dose, stepping up every 4 weeks. With a compounded multi-dose vial, the volume you draw equals your dose in milligrams divided by the vial's mg/mL concentration — so the same 1 mg dose is 40 units from a 2.5 mg/mL vial but only 10 units from a 10 mg/mL vial. This guide walks the full escalation calendar, the draw-volume arithmetic, and the small-volume measuring traps that cause real dosing errors.
Key takeaways: standard titration is 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg, one step every 4 weeks. Draw (mL) = dose (mg) ÷ concentration (mg/mL); units = mL × 100. Always confirm the concentration printed on your dispensed vial — it sets the units, not the milligram dose.
Semaglutide Calculator →The standard titration calendar
Semaglutide is escalated slowly because gastrointestinal side effects — nausea, the most common reason people stop — ease as the gut adapts. The schedule below mirrors the Wegovy (2.4 mg) weight-management label, which steps up every 4 weeks, and the lower-ceiling Ozempic diabetes schedule that tops out around 1–2 mg. Your prescriber may hold a level longer if side effects bite; that is normal and does not mean the protocol failed.
| Weeks | Weekly dose | What is happening |
|---|---|---|
| 1–4 | 0.25 mg | Tolerance-building dose; not yet therapeutic |
| 5–8 | 0.5 mg | First step up if 0.25 mg was tolerated |
| 9–12 | 1.0 mg | Common stopping point on diabetes protocols |
| 13–16 | 1.7 mg | Intermediate weight-management step |
| 17+ | 2.4 mg | Full weight-management maintenance dose |
If a step is poorly tolerated, a prescriber may repeat the previous dose for another 4 weeks rather than push forward. That is why two people on "week 12" can be on different doses — the calendar is a guide, not a contract.
How this is calculated
Every compounded vial states a concentration in milligrams per milliliter. One U-100 insulin unit is 0.01 mL, so 100 units fill 1 mL. The two formulas you need:
- Draw volume (mL) = dose (mg) ÷ concentration (mg/mL)
- Syringe units = draw volume (mL) × 100
That is the whole maths. The milligram dose your prescriber sets never changes with concentration — but the units you draw change a lot, because a stronger vial packs the same milligrams into less liquid. This is exactly where measuring errors creep in, so work the numbers for your specific vial every time the concentration changes.
Worked examples for every titration step
Draw = 0.25 ÷ 2.5 = 0.10 mL
0.10 mL = 10 units
Draw = 0.5 ÷ 5 = 0.10 mL
0.10 mL = 10 units
Draw = 1.0 ÷ 10 = 0.10 mL
0.10 mL = 10 units — note three different doses can all read "10 U" on different vials
Draw = 1.7 ÷ 5 = 0.34 mL
0.34 mL = 34 units
Draw = 2.4 ÷ 2.5 = 0.96 mL
0.96 mL = 96 units — almost a full 1 mL syringe; a stronger vial is far easier to measure
Draw = 2.4 ÷ 10 = 0.24 mL
0.24 mL = 24 units — same dose, one-quarter the volume of the 2.5 mg/mL vial above
Draw = 0.25 ÷ 10 = 0.025 mL
2.5 units — falls between graduations; the same dose is 10 U on a 2.5 mg/mL vial, far easier to read
Dose-to-units reference chart
The complete grid below cross-references every standard dose against the three common compounded concentrations. Round to the nearest readable graduation and re-derive it whenever your pharmacy changes the vial strength.
| Dose | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|
| 0.25 mg | 0.10 mL · 10 U | 0.05 mL · 5 U | 0.025 mL · 2.5 U |
| 0.5 mg | 0.20 mL · 20 U | 0.10 mL · 10 U | 0.05 mL · 5 U |
| 1.0 mg | 0.40 mL · 40 U | 0.20 mL · 20 U | 0.10 mL · 10 U |
| 1.7 mg | 0.68 mL · 68 U | 0.34 mL · 34 U | 0.17 mL · 17 U |
| 2.4 mg | 0.96 mL · 96 U | 0.48 mL · 48 U | 0.24 mL · 24 U |
Why concentration causes dosing errors
The FDA has warned that compounded injectable semaglutide has caused overdoses, some needing hospitalisation, when patients or clinicians mis-measured the dose — drawing milligrams as if they were units, or reusing a units number from a different-strength vial. The defense is simple: never carry a units figure between vials. A 0.5 mg dose is 10 units from a 5 mg/mL vial and 20 units from a 2.5 mg/mL vial; the milligrams are identical, the syringe mark is not. Compounded vials are also not FDA-approved finished products, so the label strength is the only number you can rely on.
Compounded vials vs brand pens
Brand-name semaglutide (Ozempic, Wegovy) ships in pre-filled, pre-dosed pens — you dial a click, not a volume. Compounded semaglutide ships as a multi-dose vial you draw from with an insulin syringe, which is why the maths above only applies to vials. Compounded products have also been described as semaglutide base, sodium, or acetate salts; these can differ in assumed potency, so never convert between forms yourself. Use the concentration on the dispensed vial and ask the pharmacy if the wording is unclear.
Preparation, storage and missed doses
Clean the septum with alcohol and let it dry, draw your calculated volume, expel air bubbles, then inject subcutaneously into the abdomen (5 cm clear of the navel), thigh, or upper arm — rotating sites weekly. Store vials refrigerated at 2–8°C, protected from light, and never frozen; some formulations tolerate limited room-temperature time, but follow the pharmacy label. If a weekly dose is missed and the next is more than 48 hours away, many labels advise taking it promptly; otherwise skip it and resume the schedule. Never double up to "catch up" unless your prescriber tells you to.
So, how does semaglutide dosing work?
Semaglutide is dosed once weekly, starting at 0.25 mg for the first 4 weeks, then stepping up every 4 weeks through 0.5, 1.0, 1.7, and finally 2.4 mg for weight management (or stopping around 1–2 mg on diabetes protocols). With a compounded vial, the draw volume is simply your dose in milligrams divided by the vial’s concentration in mg/mL, then multiplied by 100 for U-100 units. Use the semaglutide units calculator to convert your exact dose and vial strength in one step.
Frequently asked questions
How does semaglutide dosing work, in brief?
What dose of semaglutide do I start at?
How is compounded semaglutide different from brand-name pens?
Why does the same dose read different units on different vials?
My draw is 2.5 units — can I measure that accurately?
This is a mathematical and procedural reference, not medical advice and not a substitute for your prescriber. Compounded semaglutide is not an FDA-approved finished drug product; dosing decisions, side-effect management, and titration timing must come from your clinician.
Sources
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021.
- Wegovy (semaglutide) Prescribing Information, dose-escalation Table 1. DailyMed / FDA label.
- FDA. Dosing errors associated with compounded injectable semaglutide products. FDA Drug Safety Alert, 2024.
- Kommu S, Whitfield P. Semaglutide. StatPearls. NCBI Bookshelf, 2024.
- SELECT: semaglutide reduces major cardiovascular events 20% in obesity without diabetes. Cardiology Journal. 2024.