Short answer: When you stop weight-loss injections, the active ingredient is cleared gradually: semaglutide stays in the circulation for about 5 weeks after the last dose, and tirzepatide takes roughly 4 weeks. The appetite signals the medicine was suppressing return and stomach emptying goes back to its previous pace; weight regain is common after stopping, and the decision to stop belongs with your prescriber.

Key takeaways

  • The medicine does not change your metabolism permanently; when you stop, natural hunger signals return.
  • How you stop, tapering the dose or ending it outright, is your prescriber's call; the product information does not require a taper.
  • The high-protein eating and resistance exercise habits built during treatment are worth keeping, although weight regain is still common after stopping.
  • Many prescribers choose a maintenance-dose strategy for long-term weight maintenance in many patients.

When the medicine is stopped, its effect also wears off over time: the mechanism that suppressed appetite and slowed stomach emptying comes to an end. In the STEP 1 extension study, one year after semaglutide and the study's lifestyle programme were stopped, participants had regained about two thirds of the weight they had lost. This does not mean the treatment failed; it relates to obesity being treated as a long-term condition.

The decision to stop treatment belongs to your GP or prescriber alone. Do not stop the medicine on your own; this page does not replace that conversation.

When does appetite come back?

It takes several weeks for the active ingredient to leave the body. Semaglutide has a half-life of about 1 week and stays in the circulation for about 5 weeks after the last dose; tirzepatide has a half-life of about 5 days, so it takes roughly 4 weeks. Because of this, the effect does not stop all at once but fades gradually. Most people notice in the weeks after their last dose that the feeling of fullness does not last as long and their portions go back to how they were.

Will the weight definitely come back?

It is not automatic, but it is common. In the STEP 1 extension study (Wilding et al., 2022), one year after semaglutide and the study's lifestyle programme were stopped, participants had regained about two thirds of the weight they had lost; at week 120 their net loss from the start was 5.6%. Habits formed during treatment (portion control, protein intake, regular movement) are still worth keeping, but they are not a guarantee, so the decision to stop belongs with your prescriber.

That is why it makes sense to track not just the scales but also your habits during treatment. Knowing what you changed and when also tells you what to hold on to once you are off the medicine.

How is the decision to stop made?

The length of treatment varies by person and by indication. The decision is made by weighing factors together, such as whether the goal has been reached, how well side effects are tolerated, other health conditions and access to the medicine. In some cases treatment continues at a lower dose; in others it is ended.

What if I have to take a break?

If you cannot get hold of the medicine or cannot use it for a while, tell your GP or prescriber. After a long break, treatment may not continue at the same dose; you may need to restart at a low dose and build up gradually. That decision is also made by your prescriber.

Why records help

Haftra keeps the records you logged during treatment even after you stop: how long you stayed on each dose, how your weight changed, which symptoms happened in which period. If you ever restart, this history answers most of your prescriber's questions on one screen. It is free and can be used without creating an account.

iPhone, iPad and Apple Watch. Free.

Frequently asked questions

Does the weight come back when you stop weight-loss injections?

It is not automatic, but it is common. In the STEP 1 extension study, one year after semaglutide and the study's lifestyle programme were stopped, participants had regained about two thirds of the weight they had lost. The decision to stop belongs with your GP or prescriber.

When is the medicine cleared from the body?

Semaglutide has a half-life of about 1 week and stays in the circulation for about 5 weeks after the last dose. Tirzepatide has a half-life of about 5 days, so it takes roughly 4 weeks.

When does appetite come back?

Because the half-life is long, the effect does not stop all at once but fades gradually. Most people notice in the weeks after their last dose that the feeling of fullness does not last as long.

Can I stop weight-loss injections suddenly?

Do not stop on your own. Unless there is a medical emergency, how and when to stop is decided with your GP or prescriber, who may reduce the dose gradually.

When should I stop treatment?

The length of treatment varies by person and by indication. The decision is made by weighing factors together, such as whether the goal has been reached, how well side effects are tolerated, other health conditions and access to the medicine.

If I take a break, do I carry on at the same dose?

After a long break, treatment may not continue at the same dose; you may need to restart at a low dose and build up gradually. That decision is made by your GP or prescriber.

Sources

  • EMA: Mounjaro (tirzepatide)
  • EMA: Ozempic (semaglutide)
  • EMA: Wegovy (semaglutide)
  • NHS: Obesity treatment
  • MHRA (Medicines and Healthcare products Regulatory Agency)
  • Wilding JPH et al. Diabetes Obes Metab. 2022;24(8):1553-1564

Last reviewed: 4 August 2026