Essentials · Evidence reviewed
What happens when Zepbound treatment is stopped?
Researchers in the SURMOUNT-4 trial, with Eli Lilly involvement, studied a question many patients eventually face: what happens to weight after treatment is stopped? Participants first received tirzepatide for 36 weeks. Those who completed that phase were then randomly assigned either to keep taking the medicine or switch to placebo for 52 more weeks.
Who conducted the study?
SURMOUNT-4 was a randomized withdrawal trial investigating tirzepatide, supported by Eli Lilly. Everyone initially received active medicine for 36 weeks. Only participants who completed this lead-in were randomized to continue treatment or switch to placebo, making this a study of maintenance after an initial treatment response.
What happened after the groups separated?
The randomized group had lost about 20.9% of initial body weight on average during the lead-in. Over the following 52 weeks, people continuing tirzepatide lost a further average 5.5% relative to their randomization weight, whereas the placebo group regained an average 14.0% relative to that weight. These numbers have different starting points and should not simply be added together.
Does that mean stopping is impossible?
No. The trial reports group outcomes under specific research conditions; it does not determine the best plan for any individual. People may need to change or stop a medicine for side effects, pregnancy planning, medical concerns, access or personal preferences. Those decisions need a clinician's input.
What is the practical takeaway?
Before treating the target weight as a finish line, discuss how you will maintain progress. Ask about clinical follow-up, likely long-term cost, treatment tolerance and what to do if weight begins increasing after a change.
The bottom line
In this trial, continuing tirzepatide maintained or extended weight loss, while withdrawal was followed by substantial average regain.
Written and published by MyDosePro as an educational explanation of publicly available evidence. The linked primary source is dated 2023-12-11. We identify trial registrations separately from published results and do not provide individual prescribing advice.
Primary sourceThis guide explains published evidence; source dates may be older than the review date. Our interpretation is educational and does not replace medical or insurance advice.