Verbatim response from Perplexity
On GLP-1 medications, most people lose 1–2 pounds per week initially, reaching an average of 15%–20% total body weight loss within the first year (with tirzepatide often yielding ~20% and semaglutide ~15%)[1][4][11][15]. Weight loss typically slows around months 4–6 and platears between 12–18 months for most patients[1][13].
Sustainability depends on continued use:
- While on the medication, weight loss is durable; studies show maintenance of 10%–20% loss for up to 2–3.5 years with ongoing therapy[1][2][5].
- After stopping, weight regain is rapid: patients regain ~60% of lost weight within 1 year and stabilize at ~75% regain long-term[3]. On average, people regain nearly 2 pounds/month after discontinuation[13].
- Only a minority (roughly 25% of the acute loss) stays off permanently without the drug, equating to 4%–5% of total body weight retained long-term[3].
Key factors for success:
- Ongoing medication is required for most to maintain results[1][2][3].
- Lifestyle changes (nutrition, physical activity) are essential; GLP-1s do not replace the need for these[9].
- Real-world results may be lower than clinical trials (e.g., 8.7% average loss at 1 year vs. 15%–20% in trials), especially if doses aren’t maximized or support is limited[7][8].
For sustainable outcomes, most patients need long-term treatment combined with lifestyle modifications.