Why a conversion tool exists
FDA-approved Wegovy comes in pens that deliver a fixed dose. Compounded semaglutide comes in a multi-dose vial, and the patient draws up each dose with an insulin syringe marked in units. Units measure volume — 100 units is 1 mL on a U-100 syringe — and the amount of drug in a given volume depends on the concentration the pharmacy used, which varies from vial to vial and pharmacy to pharmacy. The FDA has received reports of patients taking five, ten and twenty times the intended dose after confusing units with milligrams or using a units figure meant for a different concentration. This tool exists to catch that error.
How to use it
Find the concentration on your vial label, written as mg/mL (for example 2.5 mg/mL or 5 mg/mL). Enter it with the dose your clinician prescribed. The result is the volume in mL and the equivalent units. Compare it with your pharmacy's written instructions. If they differ, do not inject; call the pharmacy. If your label does not state a concentration, do not inject; ask for it in writing.
What the tool will not do
It will not suggest a dose, escalate a dose, or convert between semaglutide products. The labeled Wegovy schedule is shown for reference only. See semaglutide units vs milligrams for the full explanation.