Semaglutide microdosing chart, in units.

The small-dose problem

Semaglutide's common amounts are a fraction of tirzepatide's — 0.125 mg, 0.25 mg, 0.5 mg. At a typical 2.5 mg/mL concentration, 0.125 mg is 5 units and 0.25 mg is 10. That's readable. Reconstitute a 5 mg vial with 1 mL instead and 0.125 mg becomes 2.5 units, which is guesswork on any syringe. With semaglutide, more water is almost always the right call, and the calculator will say so when a dose drops under 5 units.

Worked example, 5 mg vial in 2 mL

• 0.125 mg → 5 units · 40 doses
• 0.25 mg → 10 units · 20 doses
• 0.5 mg → 20 units · 10 doses
• 1 mg → 40 units · 5 doses
• 2 mg → 80 units · 2.5 doses

Units versus milligrams versus pens

Pharmacy pens are labelled in milligrams per click. Research vials are labelled in total milligrams and you set the concentration yourself. That's the whole reason "semaglutide chart in units" is a search: the two systems don't talk to each other. Units are volume — 0.01 mL each on a U-100 syringe — and only mean something once you know the mg/mL.

Not covered here

Whether to use semaglutide, at what dose, or on what schedule. Those are prescriber questions. This page converts numbers; it doesn't choose them.