Calculator
GLP-1 dose-level plotter
Short answer
The plotter sums a Bateman curve for every dose: A(t) = Σ D·ka/(ka−ke)·(e^(−ke·τ) − e^(−ka·τ)), with ke = ln2 ÷ half-life. Example: retatrutide (t½ 6 days) at 2 mg weekly for 4 weeks gives 1.5954 mg-eq on day 28. Relative amount, not plasma concentration; modeled estimate as of Oct 19, 2026.
- Peak amount
- 19.67 mg-eq
- Stable window from
- Day 126
- Stable average
- 14.64 mg-eq
- Accumulation R
- 1.803×
- Dose ladder: mg per dose for each tier
- One tick per dose; an open circle is a missed dose
- Modeled relative amount in mg-equivalents (F = 1), not plasma concentration
- Stable window: weekly troughs change by under 5%
Day 190: 19.665 mg-eq modeled. Move the slider or hover the chart for the per-dose breakdown.
Weekly data table
| Week | Starts | Dose mg | Peak | Trough | Average |
|---|---|---|---|---|---|
| 1 | Oct 19, 2026 | 2 | 1.782 | 0 | 1.287 |
| 2 | Oct 26, 2026 | 2 | 2.608 | 0.921 | 1.945 |
| 3 | Nov 2, 2026 | 2 | 2.978 | 1.331 | 2.238 |
| 4 | Nov 9, 2026 | 2 | 3.144 | 1.514 | 2.368 |
| 5 | Nov 16, 2026 | 4 | 4.993 | 1.595 | 3.713 |
| 6 | Nov 23, 2026 | 4 | 5.857 | 2.553 | 4.397 |
| 7 | Nov 30, 2026 | 4 | 6.244 | 2.979 | 4.701 |
| 8 | Dec 7, 2026 | 4 | 6.417 | 3.169 | 4.837 |
| 9 | Dec 14, 2026 | 6 | 8.266 | 3.254 | 6.184 |
| 10 | Dec 21, 2026 | 6 | 9.134 | 4.212 | 6.869 |
| 11 | Dec 28, 2026 | 6 | 9.521 | 4.639 | 7.174 |
| 12 | Jan 4, 2027 | 6 | 9.694 | 4.829 | 7.31 |
| 13 | Jan 11, 2027 | 9 | 12.43 | 4.914 | 9.3 |
| 14 | Jan 18, 2027 | 9 | 13.714 | 6.333 | 10.314 |
| 15 | Jan 25, 2027 | 9 | 14.288 | 6.966 | 10.766 |
| 16 | Feb 1, 2027 | 9 | 14.544 | 7.247 | 10.967 |
| 17 | Feb 8, 2027 | 12 | 17.315 | 7.373 | 12.987 |
| 18 | Feb 15, 2027 | 12 | 18.617 | 8.81 | 14.013 |
| 19 | Feb 22, 2027 | 12 | 19.199 | 9.45 | 14.471 |
| 20 | Mar 1, 2027 | 12 | 19.458 | 9.735 | 14.675 |
| 21 | Mar 8, 2027 | 12 | 19.573 | 9.863 | 14.765 |
| 22 | Mar 15, 2027 | 12 | 19.624 | 9.919 | 14.806 |
| 23 | Mar 22, 2027 | 12 | 19.647 | 9.944 | 14.824 |
| 24 | Mar 29, 2027 | 12 | 19.658 | 9.956 | 14.832 |
| 25 | Apr 5, 2027 | 12 | 19.662 | 9.961 | 14.835 |
| 26 | Apr 12, 2027 | 12 | 19.664 | 9.963 | 14.837 |
| 27 | Apr 19, 2027 | 12 | 19.665 | 9.964 | 14.838 |
| 28 | Apr 26, 2027 | 12 | 19.665 | 9.964 | 14.838 |
| 29 | May 3, 2027 | — | 10.356 | 4.635 | 7.119 |
| 30 | May 10, 2027 | — | 4.613 | 2.065 | 3.171 |
| 31 | May 17, 2027 | — | 2.055 | 0.92 | 1.412 |
| 32 | May 24, 2027 | — | 0.915 | 0.41 | 0.629 |
Math, parameters and sources: model card.
How the plotter models levels
Each dose is treated as a one-compartment, first-order absorption curve (the Bateman function), and the curves for every dose are added together. The rate of elimination comes from the half-life (ke = ln2 ÷ t½) and the rate of absorption is solved from the published time to peak. The result is a relative amount in mg-equivalents with bioavailability set to 1, which is why it is useful for comparing schedules and not for reading a blood level.
| Compound | t½ (days) | tmax (h) | ke (/day) | ka (/day) | R | Left after 7 d |
|---|---|---|---|---|---|---|
| Retatrutide | 6 | 24 | 0.115525 | 3.5371 | 1.8033 | 0.4454 |
| Tirzepatide | 5 | 24 | 0.138629 | 3.3122 | 1.6101 | 0.3789 |
| Semaglutide | 7 | 36 | 0.099021 | 2.1514 | 2 | 0.5 |
Published ladders preloaded
The preset buttons load schedules exactly as published. They are there so you can see what a trial or label schedule looks like on the curve; none of them is a recommendation.
| Ladder | Steps (mg, weekly) | Weeks per step | Source |
|---|---|---|---|
| Retatrutide Phase 3 12 mg arm | 2 → 4 → 6 → 9 → 12 | 4 | Eli Lilly, May 21, 2026 |
| Retatrutide Phase 3 9 mg arm | 2 → 4 → 6 → 9 | 4 | Eli Lilly, May 21, 2026 |
| Retatrutide Phase 3 4 mg arm | 2 → 4 | 4 | Eli Lilly, May 21, 2026 |
| Retatrutide Phase 2 12 mg arm | 2 → 4 → 8 → 12 | 4 | Eli Lilly, hosted on ClinicalTrials.gov, Aug 29, 2022 |
| Retatrutide Phase 2 8 mg arm (2 mg start) | 2 → 4 → 8 | 4 | Eli Lilly, hosted on ClinicalTrials.gov, Aug 29, 2022 |
| Retatrutide Phase 2 8 mg arm (4 mg start) | 4 → 8 | 4 | Eli Lilly, hosted on ClinicalTrials.gov, Aug 29, 2022 |
| Tirzepatide FDA label ladder to 15 mg | 2.5 → 5 → 7.5 → 10 → 12.5 → 15 | 4 | DailyMed, Aug 28, 2026 |
| Tirzepatide FDA label ladder to 5 mg | 2.5 → 5 | 4 | DailyMed, Aug 28, 2026 |
| Semaglutide Wegovy label ladder to 2.4 mg | 0.25 → 0.5 → 1 → 1.7 → 2.4 | 4 | Novo Nordisk, Jun 18, 2026 |
| Semaglutide Ozempic label ladder to 2 mg | 0.25 → 0.5 → 1 → 2 | 4 | Novo Nordisk, Jun 1, 2026 |
Reading the stable window
With a fixed weekly dose, each week's lowest point (the trough) rises less than the week before. The plotter shades the "stable window" from the first week in which two consecutive week-over-week trough changes are both under 5%. After any dose increase the climb restarts, so a titration ladder usually reaches its stable window only on the final step. A missed dose shows up as a dip in both the curve and the weekly table.
- First peak about 24 hours after the first dose (time to peak).
- Trough: the lowest point, just before the next weekly dose.
- Accumulation: each dose adds to what is left, so peaks and troughs climb toward about 1.8× a single dose.
- Stable window: from about day 28, the weekly trough changes by less than 5% from one week to the next.
- Washout: after the last dose the amount halves every 6 days.
Relative amount (mg-equivalents), not a blood level. Model and sources: model card.
Frequently asked questions
What is a GLP-1 dose plotter?
- A tool that draws a modeled amount of a weekly medicine over time from its half-life and absorption time, so you can see how doses overlap, how levels build after each step and when they flatten.
Which half-lives does the plotter use?
- Retatrutide 6 days (Phase 1b data), tirzepatide 5 days (FDA label) and semaglutide 7 days (FDA label, about 1 week). Each comes with its source on the model card.
Can I share a schedule?
- Yes. The page keeps your inputs in the link (for example ?c=retatrutide&s=2026-10-19&t=4-2-2-0800). Shared links are never published as separate pages; they always point search engines at the clean URL.
Does it work without JavaScript?
- The default published ladder, chart and weekly table are pre-rendered, so the page answers without JavaScript. With JavaScript, every change recalculates instantly in your browser; nothing is sent to a server.
Is retatrutide FDA approved?
- No. As of Oct 19, 2026 retatrutide is investigational. Lilly reported Phase 3 results in 2026 and said it plans to submit to the FDA in the first quarter of 2027. It is legally available only to participants in Lilly clinical trials.
Sources
- LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. The Lancet 2022;400(10366):1869-1881 (abstract via PubMed PMID 36354040; doi:10.1016/S0140-6736(22)02033-5), Oct 27, 2022. Accessed Oct 19, 2026.
- ZEPBOUND (tirzepatide) injection, for subcutaneous use - Full Prescribing Information, Medication Guide and Instructions for Use (DailyMed SPL set ID 487cd7e7-434c-4925-99fa-aa80b1cc776b, version 40). U.S. National Library of Medicine (DailyMed) / Eli Lilly and Company, Aug 28, 2026. Accessed Oct 19, 2026.
- WEGOVY (semaglutide) injection, for subcutaneous use; WEGOVY (semaglutide) tablets, for oral use - Full Prescribing Information (SPL, Revised 6/2026). Novo Nordisk / National Library of Medicine DailyMed, Jun 18, 2026. Accessed Oct 19, 2026.
- Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. Eli Lilly and Company (via PR Newswire; also investor.lilly.com), May 21, 2026. Accessed Oct 19, 2026.
The curve and figures are a modeled relative amount in the body (mg-equivalents), not a blood level.
Printed from GLP Ladder. To recreate this result, open https://glpladder.com/tools/plotter/
Questions for my clinician