How Long Does Wegovy Take to Work? Wegovy, Ozempic and Semaglutide Timelines

Appetite and food intake change within weeks, weight loss becomes measurable in the first months, and the full effect builds through week 68 or later. This table lines up the milestones the label and trials report for the Wegovy injection.

The steady-state figure comes from the Ozempic label, which describes the same molecule at its diabetes doses.2

Wegovy starts working on appetite in the first weeks, while the dose is still being raised. In a 20-week trial of 72 adults with obesity, semaglutide 2.4 mg cut food intake at an all-you-can-eat lunch by 35% compared with placebo.3 It also reduced hunger, increased fullness and lowered the strength and number of food cravings.3

Weight loss trails the appetite change. In that trial, body weight fell 9.9% with semaglutide and 0.4% with placebo by week 20.3

The first 16 weeks are a dose step-up, starting at 0.25 mg, so the full 2.4 mg dose begins in week 17 at the earliest.1 The label sets this schedule:1

• Weeks 1–4: 0.25 mg
• Weeks 5–8: 0.5 mg
• Weeks 9–12: 1 mg
• Weeks 13–16: 1.7 mg
• Week 17 onward: 2.4 mg (or 1.7 mg)

The slow climb exists to reduce stomach side effects.1 If a dose is not tolerated, the label lets prescribers delay the next step for 4 weeks, which pushes the timeline back.1 In the STEP 1 trial, nausea and diarrhea were the most common side effects and were typically transient and subsided with time.4

For adults who tolerate 2.4 mg for at least 4 weeks and need more weight reduction, the label allows an increase to 7.2 mg, sold as Wegovy HD.1 See Wegovy dosage for every step.

In the STEP 1 trial, 86.4% of people on semaglutide 2.4 mg lost at least 5% of their body weight by week 68.4 Average loss was 14.9%, or 15.3 kg, against 2.4% on placebo.4

Fast early loss is less common. In SURMOUNT-5, which compared semaglutide with tirzepatide, 21% of semaglutide participants lost at least 15% of body weight by week 24.5 The share was 44% for tirzepatide.5 Our Wegovy vs Zepbound comparison and the guide to how long Zepbound takes to work cover the other drug.

People with type 2 diabetes lost less in the label's trials: 9.6% on Wegovy 2.4 mg at week 68, against 3.4% on placebo.1 For reasons the scale can stall, see not losing weight on a GLP-1.

The Wegovy pill reaches its peak in the blood about 1 hour after each daily tablet, but it takes 90 days of step-ups to reach the 25 mg maintenance dose.1 The pill starts at 1.5 mg for 30 days, then rises to 4 mg, then 9 mg, with 25 mg from day 91.1

In the label's 64-week trial, the 25 mg tablet produced an average loss of 13.6%, against 2.4% on placebo.1 The label predicts that blood levels on the 25 mg tablet are comparable to the 2.4 mg weekly injection, with more variation between people.1 Read more in our Wegovy pill guide, or compare programs that prescribe it in our oral GLP-1 rankings.

Ozempic reaches steady blood levels after 4 to 5 weeks of weekly injections, and its trials measured the main results at week 30 or later.2 Ozempic is approved for type 2 diabetes, not weight loss.2 It starts at 0.25 mg weekly for 4 weeks, then 0.5 mg, with optional steps to 1 mg and 2 mg after at least 4 weeks on each dose.2

In the label's monotherapy trial, HbA1c fell by 1.4 points on 0.5 mg and 1.6 points on 1 mg at week 30, against 0.1 on placebo.2 Body weight fell 3.8 kg on 0.5 mg and 4.7 kg on 1 mg, against 1.2 kg on placebo.2

Ozempic and Rybelsus tablets also contain semaglutide. Their label states that steady levels are reached after 4 to 5 weeks of daily dosing.6 See Ozempic vs Wegovy for how the brands differ.

How quickly does Wegovy work on cravings? In a 20-week trial, semaglutide 2.4 mg lowered food cravings and improved control of eating compared with placebo.3 The trial did not report the exact week each change began. Our explainer on food noise covers the research.

How long does compounded semaglutide take to work? There is no label timeline for compounded semaglutide. Compounded drugs are not FDA-approved, and the figures above come from trials of the brand-name products. See compounded semaglutide and our compounded semaglutide program rankings.

What if I miss a Wegovy injection? If the next dose is more than 2 days away, take it as soon as possible. If it is less than 2 days away, skip it.1 If 2 or more doses in a row are missed, the label tells prescribers to restart the step-up at a lower dose.1

Does Wegovy keep working after the dose stops going up? In three of the label's trials, the dose was raised over 16 weeks and then held for 52 weeks, with results measured at week 68.1 Talk to your prescriber about your own progress.

How long does it take for Ozempic to work for weight loss? Ozempic is not approved for weight loss. In its label's monotherapy trial, people lost 3.8 to 4.7 kg on average by week 30.2

Wegovy results build over a year or more, so the monthly price matters. Our Wegovy cost guide breaks down pens, Wegovy HD and the pill, and cheapest Wegovy ranks where to buy. For Ozempic prices, see Ozempic cost.

This article is for information only and is not medical advice. Wegovy and Ozempic are prescription drugs with real risks and side effects. Talk to your prescriber before starting, changing or stopping any dose.