Semaglutide Half-Life Calculator
Semaglutide's terminal half-life is approximately 7 days. This calculator visualizes how levels accumulate to steady state and wash out after stopping.
Peak Level
1 mg
Half-Life
7.0 days
Steady State
~5 weeks
Full Clearance
~36 days
Semaglutide: GLP-1 receptor agonist used for weight management and type 2 diabetes. Available as Ozempic (diabetes) and Wegovy (weight loss).
For educational and research purposes only. This calculator provides estimates based on standard formulas.
Always verify calculations with your healthcare provider before use. We assume no liability for dosing errors, adverse events, or outcomes resulting from use of this tool.
What semaglutide's half-life means in practice
Semaglutide is a GLP-1 receptor agonist with a terminal elimination half-life of approximately 7 days, which is the longest among the approved injectable GLP-1s. That long half-life is engineered through fatty acid modification that lets semaglutide bind reversibly to serum albumin and resist proteolytic breakdown. The practical result is that once-weekly dosing produces unusually flat weekly profiles.
Steady state takes roughly 4 to 5 half-lives, or about 4 to 5 weeks of weekly dosing at a fixed dose. Each upward titration resets that timeline for the new dose level, which is why the SUSTAIN and STEP trial protocols hold each titration step for 4 weeks before stepping up.
With a 7-day half-life and 7-day dosing interval, your trough sits at roughly 70 percent of your peak at steady state. That ratio is meaningfully flatter than tirzepatide's 5-day half-life produces, and it's part of why the late-week trough hunger pattern reported by some semaglutide users is generally milder than what tirzepatide users describe in the days before their weekly injection.
Worked example: 1 mg weekly
At 1 mg weekly (the most common stepped-up dose between 0.5 mg and the 2.4 mg Wegovy maintenance dose), the calculator shows levels climbing through weeks 1 to 4 and flattening into a steady oscillation by week 5. Stopping at this dose leaves clinically meaningful exposure for about 5 to 6 weeks, which is one of the reasons appetite changes feel gradual rather than abrupt.
Frequently asked questions
What is semaglutide's half-life?
Semaglutide's terminal elimination half-life is approximately 7 days (168 hours). It is the longest of the currently approved GLP-1 receptor agonists, which is why once-weekly dosing produces unusually flat trough-to-peak ratios.
When does semaglutide reach steady state?
Steady state takes roughly 4 to 5 half-lives, which is about 4 to 5 weeks of weekly dosing at a fixed dose. Titration to the next dose resets the clock for that new level.
How long after my last semaglutide dose is it still active?
After one half-life (7 days) you have 50% remaining. After two (14 days) you have 25%. Clinically meaningful exposure typically persists for 5 to 7 weeks after a final injection.
What's the half-life difference between semaglutide and tirzepatide?
Semaglutide approximately 7 days, tirzepatide approximately 5 days. Semaglutide's longer tail produces slightly flatter weekly levels and slightly slower washout when stopping.
How do I time my last dose before stopping?
There is no required taper. The 7-day half-life provides a natural taper over 4 to 6 weeks. Some prescribers step down to a lower titration dose for a few weeks before fully stopping to soften the appetite rebound.
Compare with the tirzepatide half-life calculator or open the unified GLP-1 half-life calculator.
See your real semaglutide PK curve, built from your logs
Regimen logs each weekly injection and projects your personal active-level curve, with reminders and Apple Health correlation.
- Personalized PK curves
- Weekly injection reminders
- Body composition correlation
- Private, secure health data
