Verbatim response from Perplexity
Most people lose weight on GLP-1s gradually over months, not weeks: a realistic pattern is some loss by 4–8 weeks, about 5–10% by 3–6 months, and roughly 15–20% by 12 months for medications like semaglutide or tirzepatide, though individual results vary widely.[1][2][16][18]
Whether it is sustainable depends on whether you keep taking the medication and maintain supportive habits. Studies and reviews show that weight loss is often maintained while on treatment, but stopping commonly leads to substantial regain—one large 2026 analysis found patients regained about 2 pounds per month after stopping semaglutide or tirzepatide.[1][4]
Key points:
- Average total loss: semaglutide about 15% of body weight; tirzepatide about 20% on average in people without diabetes.[1]
- Timeline: the biggest loss usually happens in the first 6–12 months, then many people hit a plateau around 12–18 months.[1][2]
- Not everyone responds equally: roughly 10–15% of patients may lose little or no weight even at the maximum dose.[1]
- Long-term sustainability: it is generally best thought of as a chronic treatment, similar to blood pressure or cholesterol meds, rather than a short course you take once and stop.[1][4]
If you want, I can also give you a month-by-month expected weight-loss timeline for semaglutide vs tirzepatide, or help estimate your likely results based on your starting weight.