GLP-1 Microdosing Calculator
Compare once-weekly vs split dosing (2× or 3× per week) for Retatrutide, Tirzepatide, and Semaglutide. See how splitting your dose affects peak drug levels and may reduce side effects.
What is GLP-1 Microdosing?
Microdosing GLP-1 agonists means splitting your prescribed or planned weekly dose into 2–3 smaller injections throughout the week, rather than one large once-weekly dose.
For example, instead of injecting 6mg of Retatrutide once weekly, you might inject 3mg on Monday and 3mg on Thursday. The same total weekly dose, but a different pharmacokinetic profile.
The Science: Peak-to-Trough Ratio
The key metric in microdosing is the peak-to-trough (P/T) ratio — the difference between the highest drug level (right after injection) and the lowest (just before the next injection). A lower P/T ratio means more stable drug levels throughout the week.
Mathematical modeling based on published half-life data suggests that splitting a weekly dose into twice-weekly injections can reduce peak drug levels by 28–38% for Retatrutide and Tirzepatide, and 20–28% for Semaglutide (which has a longer 7-day half-life that naturally smooths levels).
Potential Benefits of Microdosing
- Reduced peak nausea and GI side effects that tend to spike in the first 24–48h after injection
- More stable appetite suppression throughout the week (less “wearing off” effect before next dose)
- Easier dose adjustments — finer-grained control
Why Microdosing is Not Proven
No clinical trials have studied split-dose GLP-1 protocols. This approach is based on pharmacokinetic modeling and anecdotal community reports, not randomized controlled data. Splitting doses also means more injections, which some people find inconvenient.
This calculator is for research and educational purposes only. Always consult a healthcare provider before modifying any dosing protocol.