Guide · Starting · 3 min read

What to expect in the first month

By the CalJab team, with sources · Last reviewed October 21, 2026

GLP-1 medicines act on the systems that regulate appetite; you feel full sooner, less hungry and have fewer cravings. ^1·2

The dose starts low

• Treatment starts with a low dose and goes up step by step on your doctor's plan. ^1·2
• You stay on each dose for at least 4 weeks. ^1·2
• The dose goes up slowly to make digestive side effects less likely. ¹
• If nausea or vomiting is really bothering you, talk to your doctor about delaying the next increase or going back to the previous dose. ¹
• Don't change your dose unless your doctor tells you to. ²

What can happen in the first weeks

• Nausea, diarrhea, vomiting and constipation are most common while the dose is going up and usually ease over time. ^1·2
• Going off some foods can happen too, mostly at the start and with dose increases. ³
• With less appetite, hours can pass without eating. That can mean not getting enough nutrients, or reaching for sugary food later. ³
• If your calorie intake drops very low, the risk of missing vitamins and minerals goes up. ³

Your injection day

• Once a week, on the same day if you can; any time of day, with or without food. ^1·2
• If you need to change the day, at least 3 days should have passed since your last injection. ^1·2
• Thigh, tummy or upper arm. Change the spot each week; you can use the same area but not the exact same spot. ^2·4
• If you inject into your tummy, the Mounjaro leaflet says to stay at least 5 cm from your belly button. ²
• If you miss a dose, what to do depends on the medicine; don't take two doses together to make up for it. ^1·4

In CalJab

The body map in Log dose suggests your next injection spot. If you miss a dose, the missed dose card tells you what to do based on your medicine's leaflet. Your targets show calories as a floor. You'll find which signs need a doctor in "When to see a doctor".

Make decisions about your dose with your doctor.

Written by the CalJab team, with sources. It does not replace your doctor's advice. Found a mistake? Write to support@caljab.app.