GLP-1 Plotter and Dosage Calculator
Visualize how semaglutide, tirzepatide, retatrutide and liraglutide accumulate and decline over time with a clear, interactive pharmacokinetic model.
Medically reviewed by Dr. Jaydeep Sanghani, MBBSLast reviewed August 2026
Half-life at a glance
Semaglutide
≈ 7 days
Once-weekly. Steady state ~4–5 weeks.
Tirzepatide
≈ 5 days
Once-weekly. Steady state ~4 weeks.
Retatrutide
≈ 6 days
Investigational. Phase 2 / Phase 3.
Liraglutide
≈ 13 hours
Once-daily.
Half-life is what your body uses to clear a drug. A weekly medication with a ~7-day half-life reaches steady state after about 4–5 doses. See the FDA labels linked in Sources for the exact values.
GLP-1 Plotter and dosage simulator
Visualize how semaglutide, tirzepatide, retatrutide and liraglutide accumulate in the body over time with a clear, interactive model built for education and planning.
Published half-life data
Built-in reference
Custom schedules
Offset and missed dose
Display modes
Daily and weekly
Inputs
Custom simulation
Missed dose
Simulate a skipped or delayed injection.
Current drug level
200%
Peak
200%
Lowest
55%
Average
140%
Half-life
~7 days
Typical frequency
Weekly
Brand names
Ozempic · Wegovy · Rybelsus
Week
1
Dose
1 mg
Injection date
Day 0
Peak
40%
Remaining
100%
Week
2
Dose
1 mg
Injection date
Day 7
Peak
40%
Remaining
93%
Week
3
Dose
1 mg
Injection date
Day 14
Peak
40%
Remaining
86%
Week
4
Dose
1 mg
Injection date
Day 21
Peak
40%
Remaining
79%
Week
5
Dose
1 mg
Injection date
Day 28
Peak
40%
Remaining
72%
Week
6
Dose
1 mg
Injection date
Day 35
Peak
42%
Remaining
65%
Week
7
Dose
1 mg
Injection date
Day 42
Peak
50%
Remaining
58%
Week
8
Dose
1 mg
Injection date
Day 49
Peak
58%
Remaining
51%
| Week | Dose | Injection date | Peak | Remaining |
|---|---|---|---|---|
| 1 | 1 mg | Day 0 | 40% | 100% |
| 2 | 1 mg | Day 7 | 40% | 93% |
| 3 | 1 mg | Day 14 | 40% | 86% |
| 4 | 1 mg | Day 21 | 40% | 79% |
| 5 | 1 mg | Day 28 | 40% | 72% |
| 6 | 1 mg | Day 35 | 42% | 65% |
| 7 | 1 mg | Day 42 | 50% | 58% |
| 8 | 1 mg | Day 49 | 58% | 51% |
The model uses a first-order elimination curve. Each dose adds a new contribution, and the total concentration decays over time with the selected half-life.
The formula used is C(t) = Dose × e(-kt), where k = ln(2) / half-life. This creates realistic accumulation and steady-state behavior for repeated dosing.
A helpful educational projection
Weight-loss projections are illustrative and depend on nutrition, activity, adherence and individual response. The graph above is intended for learning, not medical or dosing decisions.
Medication comparison
Compare semaglutide, tirzepatide and retatrutide for accumulation shape and half-life.
Offset days
Use this to simulate missed doses and see how the curve changes next week.
Decision support
The chart helps users understand exposure over time without replacing medical advice.
PDF export
Print or export the page for a clean summary sheet for your doctor, coach or planner.
Half-life
The half-life describes how quickly the drug concentration falls after each dose. A shorter half-life usually produces more visible swings between doses.
Steady state
Repeated dosing raises the average concentration until the body removes the same amount it receives. That is the plateau visualized in the line chart.
Accumulation
Accumulation happens when new doses arrive before the older dose has fully disappeared. The chart captures this pattern for weekly and daily schedules.
Related tools
Explore more GLP-1 and weight-loss calculators on Calqulate.
The simulation uses a first-order elimination model. Each dose contributes a new exponential curve and the total concentration is the sum of all the remaining contributions.
The formula is C(t) = Dose × e(-kt) where k = ln(2) / half-life. That makes repeated dosing create accumulation and an eventual plateau.
Half-life, steady state, offset days and missed injections all shape the curve you see. The chart is best used to understand patterns rather than make treatment decisions.
Weight loss projections are illustrative only. Results depend on nutrition, activity, adherence and individual response.
This section is designed to help users understand how medication exposure and body-weight trends can be viewed together in a simple educational format.
Frequently Asked Questions
Common questions and answers about this calculator.
What is a GLP-1 plotter?
A GLP-1 plotter is an educational visualization of how a medication accumulates and declines over time based on its half-life and dosing schedule.
How accurate is a GLP-1 plotter?
The chart is a simplified pharmacokinetic simulation. It is useful for understanding patterns, but it does not replace clinical guidance or a prescriber's instructions.
What are offset days?
Offset days let you model delayed or missed injections so you can see how the estimated concentration changes when a dose is later than planned.
How long does semaglutide stay in the body?
Semaglutide is commonly described as having a half-life of about seven days, which is why weekly dosing is common and steady-state buildup becomes visible over several weeks.
How long does tirzepatide stay in the body?
Tirzepatide is commonly described as having a shorter half-life than semaglutide, which can make the curve look somewhat more dynamic between doses.
When does a GLP-1 medication reach steady state?
Steady state typically emerges after several repeated doses, often around the fifth week or later depending on the medication and schedule.
Can I compare semaglutide and tirzepatide?
Yes. The plotter lets you switch medications and compare the shape of the concentration curve, half-life and accumulation pattern.
Can I download the chart as a PDF?
The page includes a print-friendly workflow for downloading a PDF style summary that can be shared with a clinician or coach.
Does this calculator predict weight loss?
It includes an illustrative weight projection module for education, but it does not guarantee any specific weight-loss outcome.
Is this tool suitable for retatrutide?
The plotter includes retatrutide as an educational comparison. It should be used as a general reference and not as a dosing decision tool.
Primary sources
Half-life and dosing values used above come from the FDA-approved prescribing information for each drug. Every URL resolves to the regulator or publisher directly.
Tool Information
August 2026
Dr. Jaydeep Sanghani
Meet Akabari
Dr. Jaydeep Sanghani
MBBS, MD, DNB(Anaesth.), PDCC(CCM), DrNB(CCM)
AIIMS Bhubaneswar · AIIMS Rishikesh
Critical care specialist and anesthesiologist with advanced training from AIIMS. Reviews health calculators at Calqulate to ensure medical accuracy and evidence-based standards.