How to read it

The line is your estimated level as a share of the highest point on the chart. It isn't milligrams and it isn't a blood test. Two people on the same dose won't have the same curve, and this one knows nothing about your body.

Each shot peaks a day or more after you take it, then fades slowly. When the next one comes, part of the last shot is still there. So over the first weeks the level climbs a bit higher each time before it settles. The dashed part is after today. It only counts the shots you entered, so with none ahead it simply shows the level falling.

Semaglutide half-life

About one week. The Ozempic and Wegovy labels both give it, in section 12.3, and put the peak 1 to 3 days after a shot. The calculator takes the middle of that window, 2 days.

Tirzepatide half-life

About five days, on the Mounjaro and Zepbound labels. They put the peak between 8 and 72 hours after a shot, and the calculator takes the middle, 40 hours.

What about compounded?

The labels describe the brand-name products. Compounded versions use the same molecule but aren't FDA-approved, and nobody has published their curve. Treat the line as an even rougher sketch, and enter your dose in milligrams, not in units on the syringe.

What it can't tell you

Whether to take a shot, skip one or change your dose. Those are questions for the person who prescribes it. Your label also has a section on what to do after a missed dose.

Sources

The model: one compartment, first-order absorption. Elimination comes from the label's half-life. Absorption is solved so the peak lands in the middle of the label's window.