Mounjaro (tirzepatide) is a dual GIP/GLP-1 receptor agonist licensed in the UK for type 2 diabetes and weight management in adults with obesity or overweight with comorbidities. After achieving weight loss, determining the appropriate Mounjaro maintenance dose is essential to sustain benefits whilst minimising adverse effects. Unlike short-term treatments, Mounjaro typically requires ongoing administration, as discontinuation often leads to weight regain. The maintenance dose represents the lowest effective dose that preserves therapeutic outcomes—ranging from 5 mg to 15 mg weekly—tailored to individual response, tolerability, and clinical goals. Understanding maintenance dosing as part of chronic disease management helps optimise long-term success.

Understanding Mounjaro Maintenance Dosing After Achieving Weight Loss

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 and for weight management in adults with a BMI of 30 kg/m² or greater (obesity), or 27 kg/m² or greater (overweight) with at least one weight-related comorbidity, as an adjunct to diet and exercise. After achieving significant weight loss with Mounjaro, many patients and healthcare professionals consider what constitutes an appropriate maintenance dose to sustain these benefits whilst minimising potential adverse effects.

The concept of a maintenance dose refers to the ongoing treatment regimen required to preserve weight loss and metabolic improvements once initial therapeutic goals have been reached. Unlike some medications that can be discontinued after achieving target outcomes, Mounjaro typically requires continued administration to maintain its effects. Clinical evidence from the SURMOUNT-4 trial demonstrates that discontinuation often leads to weight regain, while SURPASS data shows deterioration of glycaemic control in patients with type 2 diabetes when treatment stops.

Currently, Mounjaro is available in the UK in doses ranging from 2.5 mg to 15 mg, administered once weekly via subcutaneous injection. The maintenance dose is not necessarily the maximum dose; rather, it represents the lowest effective dose that maintains therapeutic benefits whilst optimising tolerability. This individualised approach recognises that patients respond differently to tirzepatide, and factors such as baseline weight, comorbidities, tolerability, and treatment goals all influence the optimal long-term dosing strategy.

It's important to note that NHS access to Mounjaro for weight management is subject to NICE eligibility criteria and specialist weight management service pathways, which may differ from the marketing authorisation. Understanding that weight management with Mounjaro is a chronic treatment approach—similar to managing other long-term conditions—helps set realistic expectations. The maintenance phase represents a shift from active weight reduction to weight stabilisation and metabolic optimisation, requiring ongoing commitment and clinical oversight.

Recommended Maintenance Dose Strategies for Long-Term Weight Management

The MHRA-approved dosing schedule for Mounjaro involves gradual dose escalation, typically starting at 2.5 mg once weekly and increasing in 2.5 mg increments every four weeks as tolerated. For weight management specifically, the licensed maintenance doses are 5 mg, 10 mg or 15 mg once weekly, depending on individual response and tolerability. The 7.5 mg and 12.5 mg doses are primarily titration steps to improve tolerability when increasing to higher doses.

Key maintenance dosing principles include:

• Individualisation: The optimal maintenance dose varies between patients. Some individuals maintain weight loss effectively on 5 mg weekly, whilst others require 10 mg or 15 mg to prevent weight regain.

• Gradual titration: Even during maintenance, dose adjustments should follow a gradual approach. Rapid increases may compromise tolerability, whilst abrupt reductions risk loss of therapeutic effect.

• Response-based adjustment: Regular monitoring of weight, metabolic parameters (such as HbA1c in diabetic patients), and tolerability should guide maintenance dosing decisions.

• Minimum effective dose: Clinical practice increasingly favours identifying the lowest dose that maintains therapeutic benefits, balancing efficacy with cost-effectiveness and side effect profile.

NICE guidance emphasises that weight management interventions, including pharmacotherapy, should be part of a comprehensive approach incorporating dietary modification, physical activity, and behavioural support. The maintenance dose of Mounjaro should therefore be considered within this broader context, with ongoing lifestyle interventions remaining essential for sustained success. NICE also specifies continuation criteria that must be met for ongoing NHS treatment, including minimum weight loss thresholds at specified timepoints.

Healthcare professionals typically review treatment response during the maintenance phase according to NICE recommendations and local protocols, adjusting the dose based on weight trajectory, metabolic outcomes, and patient-reported tolerability. All dosing should follow the UK SmPC and be individualised to the minimum effective dose.

Clinical Evidence Supporting Continued Mounjaro Treatment

Clinical trial data from the SURMOUNT programme, which evaluated tirzepatide for weight management in adults with obesity or overweight with weight-related comorbidities, provides robust evidence for maintenance dosing strategies. The SURMOUNT-1 trial demonstrated that participants who continued tirzepatide treatment maintained substantial weight loss over 72 weeks, with those on 10 mg and 15 mg doses achieving mean weight reductions of approximately 19.5% and 20.9% respectively from baseline.

Crucially, extension studies and the SURMOUNT-4 withdrawal trial have shown that sustained treatment is necessary to maintain these benefits. When tirzepatide is discontinued, weight regain typically occurs, with patients recovering a significant proportion of lost weight within months. This pattern mirrors findings with other GLP-1 receptor agonists and underscores the chronic nature of obesity as a disease requiring ongoing pharmacological management.

For patients with type 2 diabetes, the SURPASS clinical trial programme demonstrated that continued tirzepatide treatment maintains glycaemic control alongside weight management benefits. The durability of HbA1c reductions and weight loss over 40–52 weeks of treatment supports the use of maintenance dosing rather than treatment discontinuation once targets are achieved.

Real-world evidence from UK clinical practice is still emerging as the medication is relatively new for weight management. The evidence base consistently supports the principle that Mounjaro maintenance therapy, when combined with lifestyle interventions, offers superior long-term weight management compared to lifestyle modification alone or treatment discontinuation after initial weight loss. Definitive long-term cardiovascular outcome data in obesity are pending, with several outcome trials currently underway.

Monitoring and Adjusting Your Maintenance Dose

Effective maintenance therapy with Mounjaro requires systematic monitoring to ensure ongoing efficacy and safety. Healthcare professionals typically establish a monitoring schedule during the maintenance phase, which may be less frequent than during dose escalation but remains essential for optimising outcomes.

Key monitoring parameters include:

• Body weight: Regular weight measurements help identify whether the current dose maintains weight loss or whether adjustment is needed. Weight regain may prompt dose review, though specific thresholds for intervention should be discussed with your healthcare provider.

• Metabolic markers: For patients with type 2 diabetes, HbA1c should be monitored in line with NICE guidance (typically every 3–6 months). Lipid profiles and blood pressure should also be assessed periodically, as these often improve with sustained weight loss.

• Tolerability assessment: Ongoing evaluation of gastrointestinal symptoms, injection site reactions, and other adverse effects helps determine whether dose reduction might improve quality of life without compromising efficacy.

• Renal function: Monitoring of kidney function may be advisable, particularly in patients with pre-existing impairment or those at risk of dehydration, as tirzepatide can be associated with gastrointestinal side effects that may lead to fluid loss.

Dose adjustments during maintenance may be warranted in several scenarios. If weight loss plateaus or reverses despite good adherence to lifestyle measures, increasing the dose (if not already at maximum) may be considered. Conversely, if a patient experiences persistent side effects or has achieved weight loss beyond their target, cautious dose reduction under medical supervision may be appropriate.

Patients should maintain regular contact with their healthcare team and report any significant changes in weight, symptoms, or overall health. Self-monitoring of weight between appointments can provide valuable data to inform dosing decisions. It is important to note that dose adjustments should never be made without consulting a healthcare professional, as inappropriate changes may compromise treatment efficacy or safety.

Managing Side Effects During Maintenance Therapy

Whilst many patients tolerate Mounjaro well during maintenance therapy, gastrointestinal adverse effects remain the most commonly reported issues. These typically include nausea, diarrhoea, constipation, vomiting, and abdominal discomfort. Fortunately, these symptoms often diminish over time as the body adapts to treatment, and they tend to be less severe during maintenance compared to the initial dose escalation phase.

Practical strategies for managing common side effects include:

• Dietary modifications: Eating smaller, more frequent meals; avoiding high-fat, spicy, or heavily processed foods; and staying well-hydrated can reduce gastrointestinal symptoms. Some patients find that reducing portion sizes helps manage nausea.

• Timing of administration: Injecting Mounjaro at a consistent time each week, potentially before a lighter meal or at bedtime, may help some individuals better tolerate the medication.

• Symptomatic treatment: Over-the-counter remedies such as antacids for mild dyspepsia or anti-diarrhoeal medications (used judiciously) may provide relief. However, patients should consult their pharmacist or GP before starting any new medications.

• Dose optimisation: If side effects persist and significantly impact quality of life, discussing dose reduction with a healthcare provider may be appropriate. Some patients find that a slightly lower maintenance dose offers an acceptable balance between efficacy and tolerability.

Less common but more serious adverse effects require prompt medical attention. These include severe abdominal pain (which may indicate pancreatitis or gallbladder disease), persistent vomiting leading to dehydration, jaundice, or symptoms of thyroid issues (such as a lump in the neck, hoarseness, or difficulty swallowing). The UK SmPC notes that tirzepatide has been associated with thyroid C-cell tumours in rodents, though the relevance to humans is unknown. Patients should be counselled to report any thyroid symptoms promptly.

Patients should also be aware of the risk of gallbladder disease (stones or inflammation) and seek immediate care for persistent right upper quadrant pain, fever, or jaundice. For those with diabetes, rapid improvement in blood glucose may worsen diabetic retinopathy; prompt ophthalmic review is advised for any visual symptoms, especially in those with pre-existing retinopathy.

Women should note that tirzepatide can reduce exposure to oral contraceptives during initiation and for 4 weeks after each dose increase; consider non-oral contraceptive methods or additional barrier protection during these periods.

Patients should also be aware of the risk of hypoglycaemia, particularly if taking Mounjaro alongside other glucose-lowering medications such as sulfonylureas or insulin. Recognising symptoms of low blood sugar—including tremor, sweating, confusion, and palpitations—and knowing how to respond is essential for safety.

Suspected adverse reactions should be reported via the MHRA Yellow Card Scheme.

When to Consult Your Healthcare Provider About Dose Changes

Knowing when to seek professional guidance regarding Mounjaro maintenance dosing is crucial for safe and effective long-term treatment. Patients should contact their GP, practice nurse, or specialist diabetes/weight management service in several specific circumstances.

Situations requiring healthcare provider consultation include:

• Inadequate weight maintenance: If you experience significant weight regain despite adherence to lifestyle measures, your maintenance dose may need review and possible adjustment.

• Persistent or severe side effects: Ongoing gastrointestinal symptoms that interfere with daily activities, quality of life, or nutritional intake warrant medical review. Dose reduction or additional supportive measures may be beneficial.

• Urgent red flags: Seek immediate medical attention for severe abdominal pain (pancreatitis/gallbladder disease), persistent vomiting/dehydration, jaundice, significant visual changes, neck mass/hoarseness/dysphagia, or signs of allergic reaction.

• Changes in health status: New medical conditions, changes to other medications, pregnancy planning, or development of complications (such as kidney disease progression) all necessitate reassessment of Mounjaro therapy.

• Hypoglycaemic episodes: If you experience symptoms of low blood sugar, particularly if recurrent, your diabetes medications may require adjustment. Never alter doses of any diabetes medication without professional guidance.

• Difficulty accessing medication: If access becomes a barrier to continuing treatment, discuss this openly with your healthcare provider. They may be able to explore NHS eligibility via specialist weight management services or other treatment options.

• Desire to discontinue treatment: If you are considering stopping Mounjaro, this decision should be made collaboratively with your healthcare team, who can discuss the likely consequences and develop a plan to minimise weight regain.

Regular scheduled reviews—typically aligned with NICE guidance and local protocols during maintenance therapy—provide opportunities to assess treatment response, discuss any concerns, and optimise your management plan. Between appointments, maintaining open communication with your healthcare team ensures that any issues are addressed promptly. Remember that Mounjaro is prescribed as part of a comprehensive weight management programme, and your healthcare providers are partners in supporting your long-term health goals. Never adjust your dose independently, as this may compromise both safety and treatment effectiveness.

Frequently Asked Questions