GLP-1 Medications Explained: What Happens When You Stop and How to Keep the Weight Off

You’ve probably heard the names Ozempic, Wegovy, or Mounjaro mentioned in conversations, in the news, or on social media. Over the last few years, GLP-1 receptor agonists have moved from a relatively niche diabetes treatment to one of the most talked-about drug classes worldwide.

In the UK alone, over 1.6 million adults used one of these medications for weight loss in a single year (13).

Whether you are considering starting a GLP-1 medication, currently using one, or thinking about what happens next, understanding both how they work and what happens after is essential for long-term health and weight management.

What Are GLP-1 medications?

Glucagon-like peptide-1 (GLP-1) is a hormone produced naturally by the gut in response to food intake (3), and it plays a central role in regulating blood glucose and appetite.

Over time, researchers identified its ability to stimulate insulin release in a glucose-dependent manner (9), making it a promising target for the treatment of type 2 diabetes. The first GLP-1-based medication, exenatide, was approved in 2005, with more recent developments, such as semaglutide and tirzepatide, improving both effectiveness and convenience (5).

Although initially developed for diabetes, these medications were later found to produce significant weight loss, which led to their use in obesity management (11).

How GLP-1 Medications Influence Appetite, Blood Sugar, and Weight

GLP-1 receptor agonists mimic the body’s natural GLP-1 hormone, but with a longer duration of action.

They reduce appetite through central mechanisms in the brain and slow gastric emptying to prolong fullness. They also improve blood glucose control by enhancing insulin secretion when needed (2, 9). They may also influence food reward pathways, reducing cravings and making it easier to regulate food intake.

Together, these effects reduce energy intake and improve metabolic health.

Interestingly, many of these same pathways are influenced by lifestyle factors such as dietary composition, sleep quality, and stress levels, all of which play a role in appetite regulation and food behaviour.

What Results Can You Expect from GLP-1 Medications?

In the STEP 1 trial, a large randomised controlled trial of the GLP-1 receptor agonist semaglutide 2.4 mg in adults with obesity, participants lost approximately 15% of their body weight over 68 weeks (9). Tirzepatide, an incretin-based therapy acting on both GLP-1 and GIP receptors, has demonstrated even greater reductions, with mean weight loss ranging from 16% to over 20% across doses (4).

In addition to weight loss, GLP-1-based therapies have been associated with improvements in blood pressure, glycaemic control, lipid profiles, and cardiovascular risk. The SELECT trial, a cardiovascular outcomes study of semaglutide in adults with obesity but without diabetes, demonstrated a 20% reduction in the rate of major adverse cardiovascular events (7). However, these benefits are closely tied to continued use.

What Happens When You Stop Taking GLP-1 Medications?

Follow-up data show that approximately two-thirds of lost weight may be regained within one year of stopping treatment (12). This is not a failure of willpower, but a predictable biological response.

After weight loss, the body adapts by increasing hunger signals and reducing energy expenditure. These changes can persist long after the initial weight loss (10). Factors such as poor sleep, high stress levels, and irregular eating patterns can further amplify these signals, making appetite more difficult to regulate.

As a result, when the medication is discontinued, appetite increases, satiety decreases, and energy intake often rises, creating conditions that promote weight regain.

Understanding this physiological response is key to developing strategies that support long-term weight stability.

How to Support Your Body After Stopping GLP-1 Medications

If medication is reduced or stopped, the focus shifts to restoring the body’s own regulatory systems. Diet plays a central role in this process. Meals that are rich in fibre, whole plant foods, and minimally processed carbohydrates tend to be more satiating and are associated with lower overall energy intake (1).

When fibre is fermented in the gut, it produces short-chain fatty acids that may stimulate endogenous GLP-1 secretion, providing a partial physiological bridge after medication is withdrawn (11).

Blood glucose stability is also important, since large fluctuations in glucose can drive hunger and increase food intake. Structuring meals to include a combination of carbohydrates, protein, and fats, while prioritising minimally processed foods, helps create a more stable metabolic environment (8).

Sleep and stress are often overlooked, but both influence appetite-regulating hormones and food choices. Poor sleep and chronic stress can increase hunger and cravings, making weight maintenance more difficult even when dietary strategies are in place.

Protecting Muscle Mass to Support Long-Term Metabolic Health

Maintaining lean body mass is another key factor. Weight loss is not exclusively fat loss, and reductions in muscle mass can lower resting metabolic rate. As a result, even with a lower caloric intake, energy expenditure may also decrease due to reduced muscle tissue.

Adequate protein intake and resistance-based physical activity can help mitigate this. Higher protein diets have been shown to support satiety and improve weight maintenance outcomes (6), while resistance training helps preserve muscle mass and support metabolic rate.

Regular movement, more broadly, such as walking and yoga, also contributes to energy balance and long-term weight stability.

Building Daily Habits for Long-Term Weight Stability

In practice, maintaining weight loss is less about strict dieting and more about building consistent routines that support appetite regulation.

A typical day might include a plant-based, high-fibre breakfast such as soya yoghurt or oats with berries and seeds. Meals can be structured around whole grains, legumes or tofu, vegetables, and healthy fats, supporting satiety and blood glucose stability. If snacks are needed, combining protein and fibre can help reduce large fluctuations in hunger.

Alongside nutrition, regular physical activity, prioritising sleep, and maintaining structured daily routines all contribute to a more stable internal environment. Over time, these behaviours help support the same appetite-regulating pathways targeted by GLP-1 medications. If you’d like to explore how these principles fit into a broader, structured approach, I explore this in more detail in my 6 Pillars of Lifestyle Medicine series.

Do GLP-1 Medications Need to Be Taken Long Term?

It is important to recognise that there is no single approach that works for everyone. The most effective strategy will depend on an individual’s metabolic health, medical history, dietary preferences, and lifestyle. For some, a gradual reduction in medication may be appropriate, while others may benefit from longer-term use alongside lifestyle interventions.

Given the complexity of this transition, personalised support can be particularly valuable in helping individuals navigate changes in appetite, behaviour, and physiology. The key point is that obesity is a chronic, biologically regulated condition, and therefore often requires an ongoing strategy rather than a one-time intervention.

I support this through one-to-one consultations, focusing on the same lifestyle factors that influence appetite, metabolism, and long-term health.

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References

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2. Drucker, D.J. (2018). ‘Mechanisms of action and therapeutic application of glucagon-like peptide-1’, Cell Metabolism, 27(4), pp. 740-756. https://pubmed.ncbi.nlm.nih.gov/29617639/

3. Holst, J.J. (2007) ‘The physiology of glucagon-like peptide-1’, Physiological Reviews, 87(4), pp. 1409-1439. https://pubmed.ncbi.nlm.nih.gov/17928588/

4. Jastreboff, A.et al. (2022). ‘Tirzepatide once weekly for the treatment of obesity’, New England Journal of Medicine, 387(3), pp. 205-216. https://pubmed.ncbi.nlm.nih.gov/35658024/

5. Knudsen, L.B. and Lau, J. (2019).‘The discovery and development of liraglutide and semaglutide’, Frontiers in Endocrinology, 10, article 155. https://pubmed.ncbi.nlm.nih.gov/30967863/

6. Leidy, H.J. et al.(2015). ‘The role of protein in weight loss and maintenance’, American Journal of Clinical Nutrition, 101(6), pp. 1320S-1329S. https://pubmed.ncbi.nlm.nih.gov/25926512/

7. Lincoff, A. et al. (2023). ‘Semaglutide and cardiovascular outcomes in obesity without diabetes’, New England Journal of Medicine, 389(24), pp. 2221-2232. https://pubmed.ncbi.nlm.nih.gov/37952131/

8. Ludwig, D.S. (2002). ‘The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease’, JAMA, 287(18), pp. 2414-2423. https://pubmed.ncbi.nlm.nih.gov/11988062/

9. Nauck, M.A. and Meier, J.J. (2019). ‘Incretin hormones: their role in health and disease’, Diabetes, Obesity and Metabolism, 21(S1), pp. 5-21. https://pubmed.ncbi.nlm.nih.gov/31144487/

10. Sumithran, P.et al. (2011). ‘Long-term persistence of hormonal adaptations to weight loss’, New England Journal of Medicine, 365(17), pp. 1597-1604. https://pubmed.ncbi.nlm.nih.gov/22029981/

11. Tolhurst, G.et al. (2012). ‘Short-chain fatty acids stimulate glucagon-like peptide-1 secretion via the G-protein-coupled receptor FFAR2’, Diabetes, 61(2), pp. 364-371. https://pubmed.ncbi.nlm.nih.gov/22190648/

12. Wilding, J.et al. (2021). ‘Once-weekly semaglutide in adults with overweight or obesity’, New England Journal of Medicine, 384(11), pp. 989-1002. https://pubmed.ncbi.nlm.nih.gov/33567185/

13. Wilding, J. et al. (2022). ‘Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension’, Diabetes, Obesity and Metabolism, 24(8), pp. 1553-1564. https://pubmed.ncbi.nlm.nih.gov/35441470/

14. University College London and Cancer Research UK (2025). 1.6 million UK adults used weight-loss drugs in the past year. https://www.ucl.ac.uk/news/2026/jan/16-million-uk-adults-used-weight-loss-drugs-past-year