According to multiple studies, the chance of regaining some, if not all, of the weight you lost is very high if you stop taking a GLP-1

Alarm symptoms that warrant urgent medical attention include: Difficulty swallowing (dysphagia) or painful swallowing (odynophagia) Unexplained weight loss not attributable to the expected therapeutic effect of Zepbound Persistent vomiting, especially if containing blood or coffee-ground material Black, tarry stools or visible blood in stool (suggesting gastrointestinal bleeding) Severe chest pain that could indicate cardiac issues rather than reflux New or worsening symptoms of anemia (fatigue, pallor, shortness of breath) Severe, persistent abdominal pain, especially if radiating to the back (possible pancreatitis) Right upper quadrant pain, fever, or jaundice (possible gallbladder disease) These symptoms may indicate complications such as esophagitis, esophageal stricture, Barrett's esophagus, or other serious conditions requiring diagnostic evaluation
Retrieved from Centers for Disease Control & Prevention (CDC)
That timeframe refers to pharmacologic clearance, while noticeable effects such as appetite suppression and blood sugar control typically fade earlier as blood levels decline