Why am I still feeling hungry on Mounjaro? Many patients taking Mounjaro (tirzepatide) for type 2 diabetes expect significant appetite suppression, yet some continue to experience hunger despite treatment. Whilst Mounjaro is a dual GIP and GLP-1 receptor agonist designed to reduce appetite and improve glycaemic control, individual responses vary considerably. Persistent hunger may relate to dosage, treatment duration, dietary factors, concurrent medications, or individual physiology. Understanding these variables helps set realistic expectations and guides appropriate management. This article explores the mechanisms behind Mounjaro's appetite effects, common reasons for ongoing hunger, and when to seek medical advice to optimise your treatment outcomes.

Understanding How Mounjaro Affects Appetite

Mounjaro (tirzepatide) is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus. Its mechanism of action involves mimicking naturally occurring incretin hormones that regulate blood glucose levels and appetite. By activating both GIP and GLP-1 receptors, Mounjaro slows gastric emptying, enhances glucose-dependent insulin secretion in response to meals, and reduces glucagon release when blood glucose is elevated.

One of the most notable effects reported by patients is a reduction in appetite and food intake. This occurs because GLP-1 receptor activation influences areas of the brain involved in appetite regulation, particularly the hypothalamus and brainstem. The slowed gastric emptying also contributes to prolonged feelings of fullness after eating, though this effect tends to diminish with continued treatment. Clinical trials have demonstrated that tirzepatide leads to significant weight reduction in many patients, largely attributed to decreased caloric intake resulting from these appetite-suppressing effects.

However, it is important to recognise that individual responses to Mounjaro vary considerably. Whilst many patients experience marked appetite suppression, others may notice more modest effects or find that hunger persists despite treatment. This variability can be influenced by numerous factors including dosage, duration of treatment, individual physiology, dietary habits, and concurrent medications. Understanding that appetite suppression is not universal helps set realistic expectations and allows patients and healthcare professionals to work together to optimise treatment outcomes. If you are experiencing persistent hunger on Mounjaro, this does not necessarily indicate treatment failure, but rather suggests the need to explore contributing factors and potential adjustments to your management plan.

Common Reasons You May Still Feel Hungry on Mounjaro

Several physiological and practical factors may explain why some individuals continue to experience hunger whilst taking Mounjaro. Insufficient time on treatment is a common consideration—the appetite-suppressing effects of tirzepatide typically develop gradually and may not be immediately apparent, particularly during the initial weeks of therapy. Some patients report that hunger reduction becomes more noticeable after several weeks at a stable dose, as the body adjusts to the medication.

Individual response to the medication plays a significant role. People may respond differently to tirzepatide based on various factors that could affect how the medication works in their body. Additionally, patients with longstanding obesity or those who have previously followed very restrictive diets may have altered hunger signalling pathways that could influence their response to incretin-based therapies.

Hypoglycaemia (low blood glucose) can cause hunger, particularly in people taking Mounjaro alongside insulin or sulfonylureas (such as gliclazide). If you experience increased hunger accompanied by symptoms like sweating, trembling, dizziness or confusion, check your blood glucose if possible and speak with your healthcare provider, as your medication regimen may need adjustment.

Hormonal factors beyond GLP-1 and GIP also regulate appetite. Multiple hormones form a complex network controlling hunger and satiety. Furthermore, psychological and behavioural eating patterns can persist independently of physiological hunger signals. Emotional eating, habitual snacking, or eating in response to environmental cues rather than true hunger may continue despite the medication's effects on appetite centres. Lifestyle factors such as poor sleep, high stress levels, and alcohol consumption can also increase appetite.

Certain concurrent medications may also influence hunger levels. Corticosteroids, some antipsychotics, and other drugs known to increase appetite could potentially diminish Mounjaro's appetite-suppressing effects. It is worth reviewing your complete medication list with your healthcare provider to identify any potential interactions or counteracting influences.

Dosage Considerations and Titration Schedule

Mounjaro is initiated at a starting dose of 2.5 mg once weekly, administered subcutaneously. This initial dose serves primarily as a tolerability step, allowing the gastrointestinal system to adapt to the medication and minimising adverse effects such as nausea, vomiting, and diarrhoea. At this introductory dose, many patients experience minimal appetite suppression, which is entirely expected and does not indicate treatment failure.

The standard titration schedule involves increasing the dose by 2.5 mg increments every four weeks, as tolerated. The maintenance doses range from 5 mg to 15 mg once weekly, depending on glycaemic control, tolerability, and treatment goals. For type 2 diabetes management, the MHRA-approved maximum dose is 15 mg weekly. It is crucial to understand that appetite suppression typically becomes more pronounced at higher maintenance doses. Patients on the initial 2.5 mg or even 5 mg dose may not yet experience the full appetite-reducing effects that become apparent at 7.5 mg, 10 mg, or higher doses.

If you are still feeling hungry on Mounjaro, consider where you are in the titration schedule. If you have recently started treatment or are on a lower dose, it may simply be too early to expect significant appetite changes. Patience during the titration phase is essential, as premature dose escalation can increase the risk of gastrointestinal side effects without necessarily improving outcomes. If side effects are problematic, your healthcare provider may delay the next dose increase or temporarily return to a lower dose.

Important safety considerations during titration:

• If you are taking insulin or a sulfonylurea alongside Mounjaro, your doctor may need to reduce these doses to prevent hypoglycaemia, particularly when starting or increasing your Mounjaro dose.

• Mounjaro may reduce the effectiveness of oral contraceptives during initiation and after each dose increase. If you use oral contraceptives, consider using a non-oral method or adding a barrier method for 4 weeks after starting Mounjaro and after each dose increase.

If you have reached a stable maintenance dose and continue to experience persistent hunger after several weeks, this warrants discussion with your healthcare provider. They may consider further dose escalation (if not yet at the maximum appropriate dose) or evaluate whether other factors are contributing to ongoing hunger. It is important never to adjust your Mounjaro dose independently—always follow your prescriber's guidance regarding titration and any dose modifications.

Dietary Factors That Influence Hunger on Mounjaro

The composition and timing of your diet can significantly influence hunger levels whilst taking Mounjaro, even when the medication is working effectively. Protein intake is particularly important—diets higher in protein tend to promote greater satiety and may work synergistically with Mounjaro's appetite-suppressing effects. Aim to include adequate protein sources (lean meats, fish, eggs, legumes, dairy products) at each meal. The current UK recommendation is approximately 0.75 g of protein per kilogram of body weight daily for adults, though individual requirements may vary. If you have chronic kidney disease, consult your healthcare provider before significantly increasing your protein intake.

Fibre-rich foods also enhance feelings of fullness by slowing digestion and stabilising blood glucose levels. The UK recommendation is 30g of fibre daily for adults. Vegetables, fruits, whole grains, and pulses provide dietary fibre that complements Mounjaro's mechanism of slowing gastric emptying. Conversely, diets high in refined carbohydrates and sugars can lead to rapid blood glucose fluctuations, potentially triggering hunger signals despite medication. Ultra-processed foods, which are often energy-dense but nutrient-poor, may not provide adequate satiety signals even when consumed in significant quantities.

Hydration status is frequently overlooked but can influence perceived hunger. Mild dehydration is sometimes misinterpreted by the body as hunger. Ensuring adequate fluid intake—typically 6–8 glasses (approximately 1.2 litres) of water daily—may help distinguish true hunger from thirst. Additionally, meal timing and frequency matter. Some patients find that eating smaller, more frequent meals helps manage hunger better than traditional three-meal patterns, whilst others prefer fewer, larger meals. Experimenting with meal timing, within the context of your overall caloric and nutritional needs, may help optimise satiety.

Moderating alcohol intake is also important, as alcohol can stimulate appetite and add extra calories without nutritional benefit. It is also worth noting that caloric restriction that is too severe can be counterproductive. Whilst Mounjaro facilitates weight loss through reduced appetite, excessively restrictive eating may trigger compensatory hunger mechanisms and is not sustainable long-term. Working with a dietitian to develop a balanced, nutritionally adequate eating plan tailored to your individual needs can maximise the benefits of Mounjaro therapy. The NHS Eatwell Guide provides a good starting point for balanced meal planning.

When to Speak with Your Healthcare Provider

Whilst some degree of hunger on Mounjaro may be normal, particularly in the early stages of treatment, certain situations warrant prompt discussion with your GP or diabetes specialist. If you have been on a stable maintenance dose for more than 4–6 weeks and continue to experience significant hunger with no reduction in appetite, this should be reviewed. Your healthcare provider can assess whether further dose titration is appropriate or whether other factors require investigation.

Inadequate glycaemic control alongside persistent hunger is particularly important to address. If your HbA1c levels are not improving as expected, or if you are experiencing symptoms of hyperglycaemia (increased thirst, frequent urination, fatigue), contact your healthcare team. These signs may indicate that your current diabetes management plan requires adjustment, which could involve increasing your Mounjaro dose, adding or modifying other glucose-lowering medications, or investigating other contributing factors.

Hypoglycaemia symptoms such as sweating, trembling, hunger, confusion, or dizziness require prompt attention, especially if you are taking Mounjaro with insulin or a sulfonylurea. Check your blood glucose if possible and seek medical advice if you experience recurrent episodes, as your medication doses may need adjustment.

You should also seek medical advice if you experience unexpected weight gain or inability to lose weight despite adherence to Mounjaro and lifestyle modifications. Whilst weight loss is not the primary indication for Mounjaro in type 2 diabetes, significant weight reduction is commonly observed. Persistent hunger accompanied by weight gain may suggest issues such as thyroid dysfunction, other hormonal imbalances, or medication interactions that require investigation.

Gastrointestinal symptoms that interfere with eating or nutrition should be reported. Whilst nausea and reduced appetite are common with Mounjaro, severe or persistent vomiting, inability to maintain adequate nutrition or hydration, or signs of pancreatitis (severe abdominal pain radiating to the back, nausea, vomiting) require urgent medical attention. Gallbladder symptoms such as sudden severe pain in the upper right abdomen, fever, or yellowing of the skin or eyes also warrant immediate medical assessment.

If you are considering stopping Mounjaro due to persistent hunger or perceived lack of effectiveness, discuss this with your healthcare provider first rather than discontinuing independently. They can help determine whether adjustments to your treatment plan might address your concerns whilst maintaining the benefits of therapy for your diabetes management.

Report any suspected side effects to the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk), which helps monitor the safety of medicines in the UK.

Frequently Asked Questions