GLP-1 Medication Level Plotter
A half-life chart assumes a perfect schedule. Real life has late shots, a skipped week and changed amounts. Enter the doses you actually took and this plotter draws an estimated medication level from your own history, so you can see what a missed week or a late shot did to the curve.
Modeled half-life 7 days, peak about 36 hours after a dose.
Your doses
Day of each shot (day 1 is your first entry) and the amount. Use your own unit; the chart is relative, so the shape is what matters.
Estimated peak
At the end of the chart
Doses plotted
4
Longest gap between doses
7 days
Below 10% of peak
25 days after last dose
A modelled estimate of relative levels from a published population half-life and time to peak. It is not a blood test, it cannot tell you what dose to take, and individual pharmacokinetics vary. Oral semaglutide (Rybelsus) absorbs differently and is not modelled here.
The default rows are relative amounts of 1 so the chart shows a shape, not a real dose. Replace them with your own history.
How the plotter builds your curve
It uses the same model as the Level chart in the Pep AI app: each dose rises to a peak and then decays with the medication's half-life, and the curve you see is every dose added together.
1. Each dose on its own
A dose ramps up to its peak over the first day or two, then falls by half every half-life. For semaglutide that half-life is about a week; for tirzepatide, about five days.
2. Doses stack
With weekly shots of a week-long half-life, about half of each dose is still present when the next arrives, so levels build over the first several weeks before leveling off.
3. Your history changes the shape
A late shot stretches the dip before it; a skipped week lets the level fall further; a changed amount raises or lowers every peak after it. The plotter shows all of that from the rows you enter.
What the curve can and cannot tell you
The curve is a model, not a blood test. It applies a published population half-life and time to peak to the doses you enter. Your own levels depend on body weight, kidney function, injection site and more, so treat the shape as informative and the exact heights as an estimate.
Where it helps is timing. People often notice appetite returning or side effects easing late in the week, and a plotted history shows where in the cycle the level is lowest. It also makes the effect of a gap visible: after several missed doses the level can fall far enough that restarting feels like starting over, which is why prescribing information tells people to contact their prescriber after a longer gap rather than simply resuming. Our guide on a missed GLP-1 dose covers what each label says.
If you want the textbook version of a perfect schedule instead, the semaglutide half-life calculator and tirzepatide half-life calculator show steady state, accumulation and clearance for a fixed interval.
The plotter does not include oral semaglutide (Rybelsus), which is taken daily and absorbed very differently, or investigational compounds. It cannot tell you what dose to take or whether to change anything; those decisions belong with your prescriber.
Frequently asked questions
More free calculators
Track this automatically with Pep AI.
Pep AI draws this curve for you from every dose you log, keeps it current as you go, and sets reminders so the gaps don't happen in the first place.
This calculator is provided for informational and educational purposes only and is not medical advice. Always confirm dosing with a qualified healthcare professional and double-check your own measurements before administering anything.
Built by the Pep AI team.