Short answer: the first few months are mostly about stepping the dose up slowly, which gives your body time to adjust. Weight loss builds gradually and kept going for more than a year in the major trials. Side effects, mostly nausea and other stomach issues, are the most common reason people struggle early on. Your prescriber sets your actual schedule.
Months 1–4: increasing the dose
Both medications start low and go up in steps, at least 4 weeks apart:
| Month | Wegovy (semaglutide) | Zepbound (tirzepatide) |
|---|---|---|
| 1 | 0.25 mg weekly | 2.5 mg weekly |
| 2 | 0.5 mg | 5 mg |
| 3 | 1 mg | 7.5 mg (if increasing) |
| 4 | 1.7 mg | 10 mg (if increasing) |
| 5+ | 2.4 mg maintenance | 5, 10 or 15 mg maintenance, max 15 mg |
The starting doses (0.25 mg and 2.5 mg) help your body adjust. They aren’t meant as long-term doses. Prescribers can slow the schedule down if side effects are hard to manage.
Common early side effects: nausea, diarrhea, vomiting, constipation and abdominal pain are the most common, per both labels. Practical habits people discuss with their care team include smaller meals, stopping eating when full, and staying hydrated. The labels warn that dehydration from vomiting or diarrhea can affect the kidneys.
Call your prescriber right away if you have severe stomach pain that won’t go away (it can spread to your back), signs of an allergic reaction, or vomiting or diarrhea you can’t keep fluids down through.
Months 4–12: the maintenance dose
Once you reach a maintenance dose, the weekly routine settles down. In the pivotal trials:
- STEP 1 (semaglutide 2.4 mg): average weight loss was 14.9% at 68 weeks.
- SURMOUNT-1 (tirzepatide 5, 10 and 15 mg): average weight loss was 15.0%, 19.5% and 20.9% at 72 weeks.
In both trials, average weight kept falling for most of the study rather than all at once. Participants also had diet and activity counseling, and results varied widely from person to person. Try the weight loss estimator to see the trial averages applied to your starting weight.
If you use vials and a syringe
Every dose step changes how many units you draw. Re-check each new dose against your vial label with the semaglutide or tirzepatide conversion pages.