What happens to your weight when you stop
Weight regain after stopping a GLP-1 treatment is common and well documented. In the semaglutide withdrawal trial, participants regained around two thirds of the weight they had lost within a year of stopping. These medicines work while they are being taken, which makes cost a long-term question rather than a course with an end date.
The short version
- Roughly two thirds of lost weight returned within a year in the withdrawal trial
- Appetite signalling returns to baseline once the drug clears
- This is a treatment, not a course — budget accordingly
- Structured support during treatment appears to soften the rebound
What the semaglutide withdrawal trial found
The STEP 1 trial extension followed participants after semaglutide was withdrawn. Within a year of stopping, participants had regained around two thirds of the weight they had lost. Cardiometabolic improvements largely reverted alongside it.
That finding has held up across the class. It is not specific to semaglutide and there is no reason to expect tirzepatide behaves differently.
Why weight returns after stopping GLP-1 treatment
GLP-1 treatments work by changing appetite signalling while they are present in the body. They do not permanently reset anything. Once the drug clears, the signalling returns to where it was.
There is a harder layer underneath. After weight loss the body reduces energy expenditure and increases appetite hormones, a set of adaptations that persists long after the weight is gone. GLP-1 treatment counteracts that while it is being taken. Stopping removes the counterweight.
None of this makes the treatment a failure. Blood pressure medication works the same way and nobody calls that a failure.
What long-term GLP-1 treatment costs in Ireland
This is the part most people work out too late. If treatment is long-term, the cost is annual rather than one-off.
| Treatment | Per pack | Approximate annual |
|---|---|---|
| Mounjaro | €554.95 | ~€3,607 |
| Wegovy | €279.95 | ~€1,820 |
| Saxenda | €106.00/pen | ~€3,816 |
Maintenance dosing, medication only, before consultation and monitoring costs.
Worth checking before you start whether you would qualify for State cover, because it changes the annual figure by an order of magnitude. The Drugs Payment Scheme →
What reduces weight regain after stopping treatment
The evidence here is weaker than the withdrawal data, so treat it as reasonable rather than proven.
- Resistance training during treatment. A meaningful share of GLP-1 weight loss is lean mass. Preserving muscle protects resting metabolic rate.
- Adequate protein. Appetite suppression makes it easy to undereat protein badly without noticing.
- Tapering rather than stopping abruptly, where your prescriber supports it.
- Habits built during treatment rather than only after. The appetite suppression is a window in which changes are easier to establish.
What to ask your prescriber before starting GLP-1 treatment
- How long would you expect me to stay on this?
- What is the plan if I need to stop for cost reasons?
- Do you support tapering, and how?
- What support is there for protecting muscle mass?
A prescriber who answers those clearly is worth more than one who does not.
Weight loss injection prices in Ireland
Every current price for all five treatments, side by side.
GuideCompare all five weight loss treatments
Cost per kilo lost, dosing and what each one is licensed for.
GuideThe Long Term Illness Scheme
Sixteen conditions, free medicines, and where GLP-1s fit.
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What long-term treatment costs across Ireland
Because the effect holds only while you are taking the medicine, the honest way to budget is per year rather than per pack. That figure does not change by county, since medication prices are set pharmacy by pharmacy rather than regionally, but what you spend around it does.
If you are attending a private clinic in Dublin or Galway, annual review fees add up on top of the medication. If your GP in Mayo or Tipperary is willing to take over repeat prescribing once you are stable, that is usually the cheapest long-term arrangement and worth asking about early rather than after a year of clinic fees.
Stopping GLP-1 treatment: common questions
Most people do. In the semaglutide withdrawal trial participants regained around two thirds of lost weight within a year of stopping. The pattern holds across the GLP-1 class.
There is no defined course length. These are treatments that work while taken rather than a fixed programme. Many prescribers frame it as long-term, which is why the annual cost matters more than the price per pack.
Some prescribers support gradual dose reduction rather than stopping outright. Evidence that tapering reduces regain is limited, but it is a reasonable conversation to have with the clinician who prescribed it.
Resistance training during treatment helps preserve lean mass, which protects resting metabolic rate. That is the most consistently supported thing you can do alongside treatment.