Short answer: With weight-loss injections, the dose is increased (titrated) step by step under medical supervision, usually in 4-week periods, so that the body can build tolerance to the medicine and digestive side effects are kept to a minimum.

Key takeaways

  • The starting dose is not a therapeutic dose; it is a low dose meant to build tolerance (for example tirzepatide 2.5 mg, semaglutide 0.25 mg).
  • Clinical guidelines recommend staying on each step for at least 4 weeks.
  • If weight loss on the current dose is satisfactory and free of side effects, the dose increase can be postponed.
  • For the first 2–3 days after a dose increase, mild nausea and loss of appetite may return.

GLP-1 treatment starts at the lowest dose, and the dose is increased gradually under medical supervision. This gradual increase is called titration. Its aim is not to speed up the effect but to reduce side effects: it gives the body time to get used to each step.

This page is for general information only and does not replace medical advice. The timing and size of dose increases are decisions for your GP or prescriber alone; do not increase or reduce the dose on your own.

Why start at the lowest dose?

These medicines slow stomach emptying and prolong the feeling of fullness. Because the effect comes directly through the digestive system, starting on a high dose noticeably increases nausea, vomiting and diarrhoea. Starting low lets you reach the same point with less discomfort.

The starting dose is usually not a treatment dose; its only purpose is to get the body used to the medicine.

What can you expect after each increase?

Side effects become noticeable again at the start of treatment and after each dose increase. So nausea that settled in the first weeks coming back on a new step is to be expected; it does not mean the treatment is going badly.

This fluctuation usually lasts a few days and eases as the body gets used to the new dose. If it carries on or is severe, tell your GP or prescriber. It can be managed by adjusting the dosing plan.

When is the dose increased?

The time between steps and the size of each step vary by product and are set out in the patient information leaflet. The shared principle is this: you do not move to the next step without spending enough time on the current one. Your prescriber may slow this schedule down depending on how you respond.

If you did not tolerate a step well, staying on it longer or going back down a step are also options. That decision is made by your prescriber.

Things to watch out for when the dose goes up

  • Smaller portions and eating slowly make the first days after an increase noticeably easier.
  • Fatty and very spicy foods can make nausea worse.
  • If you are vomiting or have diarrhoea, watch out for fluid loss; spread your drinks across the day.
  • Enough protein and regular movement are recommended to preserve muscle mass.
  • Do not speed up dose increases on your own; titration exists precisely to reduce side effects.

Tracking your steps

Recording how long you stayed on each step and how you felt after each increase helps you give clear answers to your prescriber's questions at a review appointment. Haftra keeps your dose, injection day and symptoms together; it does not suggest doses or work out dose steps. It is free and can be used without creating an account.

iPhone, iPad and Apple Watch. Free.

Frequently asked questions

What happens when the dose goes up?

Side effects such as mild nausea and loss of appetite can become noticeable again for the first few days after each dose increase. This fluctuation usually eases as the body gets used to the new dose; it does not mean the treatment is going badly.

Why start at the lowest dose?

These medicines slow stomach emptying and prolong the feeling of fullness. Starting on a high dose noticeably increases nausea, vomiting and diarrhoea. Starting low lets you reach the same point with less discomfort.

When is the dose increased?

The time between steps and the size of each step vary by product and are set out in the patient information leaflet. The shared principle is this: you do not move to the next step without spending enough time on the current one. Your prescriber may slow this schedule down depending on how you respond.

Do I have to increase the dose every month?

No. If weight loss on the current dose continues at 0.5–1% a week and your appetite control is strong, your prescriber may keep the dose the same.

What happens if I cannot tolerate a dose increase?

If you did not tolerate a step well, staying on it longer or going back down a step are also options. That decision is made by your GP or prescriber.

What is the highest maintenance dose?

The maximum weekly dose is 15 mg for Mounjaro/Zepbound and 2.4 mg for Wegovy.

Sources

  • EMA: Mounjaro (tirzepatide)
  • EMA: Ozempic (semaglutide)
  • EMA: Wegovy (semaglutide)
  • NHS: Obesity treatment
  • MHRA (Medicines and Healthcare products Regulatory Agency)

Last reviewed: 4 August 2026