How fast does GLP-1 weight loss happen?
Loss is slow during dose escalation (1–3% in the first two months), accelerates from month 3 as you reach the maintenance dose, then flattens around month 12–15.
Project your GLP-1 weight loss month by month using published trial averages for semaglutide and tirzepatide, including the plateau phase.
Projected weight = starting weight × (1 − expected total loss % × month progress curve). Semaglutide ≈ 15% at 68 weeks; tirzepatide ≈ 20%.
At 220 lb on semaglutide, a 15% average loss projects to about 187 lb after 68 weeks — roughly 8 lb in the first three months, with the fastest loss between months 4 and 9.
Loss is slow during dose escalation (1–3% in the first two months), accelerates from month 3 as you reach the maintenance dose, then flattens around month 12–15.
Your maintenance energy need falls as you lose weight, so the same dose no longer creates a deficit. Trials show plateaus around month 12; protein intake and resistance training help you push past.
Typically yes — the STEP 4 withdrawal trial saw about two-thirds of lost weight return within a year of stopping. Most clinicians treat GLP-1s as long-term therapy, not a short course.