GLP-1 Dose & Concentration Plotter

How this plotter works

The chart shows a relative plasma concentration curve for the selected GLP-1 drug across a 24-week titration timeline. The underlying math is a one-compartment pharmacokinetic model with first-order absorption and elimination — the standard Bateman equation — with linear superposition across repeated doses to capture accumulation toward steady state. The maintenance-dose steady-state peak is normalized to 100% so the chart shows relative buildup, not absolute blood levels.

The titration schedules are taken directly from each drug's FDA prescribing information for the approved drugs [1, 2, 3, 4, 5] and from the published phase 2 / phase 3 trial protocols for investigational drugs:

• Semaglutide (Wegovy / Ozempic): 0.25 mg → 0.5 mg → 1 mg → 1.7 mg → 2.4 mg, increased every 4 weeks
• Tirzepatide (Zepbound / Mounjaro): 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg, increased every 4 weeks
• Orforglipron (Foundayo): 0.8 mg → 2.5 mg → 5.5 mg → 9 mg → 14.5 mg → 17.2 mg, increased every 4 weeks
• Retatrutide (LY3437943, investigational): 2 mg → 4 mg → 6 mg → 8 mg → 10 mg → 12 mg, increased every 4 weeks. Sourced from the Jastreboff phase 2 trial (NEJM 2023) and the TRIUMPH phase 3 program protocol. Retatrutide is not yet FDA-approved; we include it for educational comparison only.

Half-life and steady state

The single most important number for understanding how a GLP-1 dose “feels” over time is the elimination half-life. For semaglutide it's about 7 days [7]. For tirzepatide, about 5 days [8]. For oral orforglipron, about 36 hours [6]. For investigational retatrutide, about 6 days [9]. After 4-5 half-lives of constant dosing the drug reaches steady state, which is the plateau the chart shows at the dashed reference line. This is why GLP-1 prescribers tell patients it can take 4-5 weeks at each dose level for the full effect to be felt.

The missed-dose simulator

For weekly drugs (semaglutide, tirzepatide), missing one dose causes plasma concentrations to drop by approximately 50% at the would-be next dose, and it usually takes 2-3 subsequent doses for levels to recover. The general FDA label guidance is: if your missed dose is less than 5 days late, take it as soon as you remember. If more than 5 days late, skip it and resume on your normal schedule [1, 3].

The missed-dose simulator below the chart lets you skip any single dose across the full 24-week window and see how the concentration curve responds.

Important disclaimer

This tool is for educational purposes only and does not constitute medical advice. The concentration curves show relative pharmacokinetic patterns based on published parameters and should not be interpreted as actual blood levels in any individual patient. Real plasma concentrations vary substantially between patients based on body weight, injection site, hepatic and renal function, drug interactions, and many other factors. Dosing decisions should always be made with a qualified healthcare provider. Weight Loss Rankings does not provide medical advice, diagnosis, or treatment recommendations.

Related research

For the clinical trial evidence behind each drug:

• Foundayo (orforglipron) FDA approval and ATTAIN-1 deep-dive
• Tirzepatide vs semaglutide head-to-head comparison
• GLP-1 side effects: what the trials actually showed
• What happens when you stop semaglutide
• GLP-1 compounded pricing index