How long does Zepbound
stay in your system?
Zepbound contains tirzepatide, the same active ingredient as Mounjaro, at the same doses and with the same ~5-day half-life. The only difference is the approved indication.
Based on Mounjaro half-life · 5 days
Related products
Zepbound is tirzepatide approved specifically for chronic weight management, the same molecule as Mounjaro under a different brand and indication. It shares the roughly 5-day half-life and the once-weekly injection schedule.
With a five-day half-life and weekly dosing, Zepbound builds toward a steady state over the first four to five weeks of treatment, with trough levels meaningfully higher than after a single first dose. This calculator models one isolated injection, useful for gauging how much of last week's dose remains rather than your full accumulated level.