The protocol at a glance
Once a week, same day each week, with or without food. The label starts low and steps up by 2.5 mg, waiting at least 4 weeks at each amount.
| Weeks | Weekly amount on the US label |
|---|---|
| 1–4 | 2.5 mg (starting amount, not a treatment dose) |
| 5–8 | 5 mg |
| 9–12 | 7.5 mg (if stepping up) |
| 13–16 | 10 mg |
| 17–20 | 12.5 mg |
| 21+ | 15 mg (maximum) |
Weight-management maintenance on the label: 5, 10 or 15 mg; for sleep apnoea 10 or 15 mg. A missed dose can be taken within 4 days, otherwise skip it. In SURMOUNT-1 everyone started at 2.5 mg and stepped up every 4 weeks.
Community reports mostly follow the label steps (2.5 mg, then 5 mg) and many stay at a lower amount longer than the label schedule if side effects build up.
What people say they do, collected from community discussions. Not tested in a trial; shown so you can compare it with the evidence above.
Mixing calculator
Enter the vial size, the water you add and the amount you want to draw; it gives the mark on a 100-unit (1 mL) insulin syringe.
What the trials found
SURMOUNT-1 (2,539 adults with obesity, no diabetes, 72 weeks). Average body-weight change:
Jastreboff AM et al., N Engl J Med 2022;387:205–16. Waist: −14.0 to −18.5 cm vs −4.0 cm on placebo.
Side effects
- Nausea, diarrhoea, vomiting, constipation, stomach pain and indigestion are the most common, mostly during step-ups.
- Label warnings include thyroid C-cell tumours (seen in rodents), pancreatitis, gallbladder problems and dehydration from stomach side effects.
- Low blood sugar is more likely when combined with insulin or sulfonylureas.
- The label says oral birth-control pills may work less well for 4 weeks after starting and after each step-up.
How it works
GLP-1 receptor
Slows stomach emptying and signals fullness to the brain.
GIP receptor
Adds to the insulin and appetite effect and acts on fat tissue.
Sources
- Zepbound and Mounjaro US prescribing information (dosing, warnings)
- Jastreboff AM et al. N Engl J Med 2022;387:205–16 (SURMOUNT-1)