There is no definitive answer yet. Retatrutide has not yet run discontinuation or maintenance trials like semaglutide (STEP 4) and tirzepatide (SURMOUNT-4).
Discontinuation data for approved drugs
Both semaglutide and tirzepatide show significant rebound after stopping. The STEP 4 trial showed that after stopping semaglutide, participants regained about two-thirds of their lost weight within 20 weeks. The SURMOUNT-4 trial showed that after stopping tirzepatide, weight regain was about two-thirds of the weight lost before discontinuation.
Why rebound is a reasonable expectation
Based on discontinuation data from similar drugs, it is reasonable to expect that retatrutide would also show similar rebound after stopping. These drugs work by continuously modulating appetite and energy metabolism. Once stopped, those modulating effects disappear, and weight regain is an expected physiological response.
But it is not a research finding
To be clear, rebound is a reasonable expectation, but it is not a retatrutide research finding. There is currently no retatrutide discontinuation trial data. Any statement about “what happens after stopping” is an inference based on similar drugs, not direct evidence.
Why this gap matters
Discontinuation is one of the core issues in long-term use of weight-loss drugs. If retatrutide is approved, patients and doctors will need to know management strategies after stopping. This gap needs to be filled in Phase III or Phase IV research.
Conclusion
There is currently no answer to the retatrutide discontinuation question. Rebound is a reasonable expectation, but the exact magnitude, timing, and individual variation still require research.