How long do GLP-1s take to start working?

Set expectations by timeline: Days 1–7: Most people notice something after the first injection — smaller appetite, earlier fullness, less snacking interest. Some feel nothing until the second or third dose; both are normal. Weeks 2–4: The scale usually starts moving — typically 2–4 lbs in the first month on starting doses. Remember that starting doses (0.25 mg semaglutide, 2.5 mg tirzepatide) are deliberately sub-therapeutic; they exist to build gut tolerance, not to maximize loss. Months 2–4: Doses climb the titration ladder and weight loss accelerates. This is where the steady ≈1–2 lbs/week rhythm typically establishes. Months 6–14: The bulk of total loss accumulates. In STEP 1, semaglutide patients were still losing meaningfully at week 60; SURMOUNT-1’s tirzepatide curves hadn’t fully flattened at week 72. If nothing happens by week 6–8 — no appetite change at all despite escalating doses — talk to your prescriber: a small minority are genuine non-responders (why am I not losing weight?), and for compounded or sublingual forms, absorption questions are worth raising.