Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist licensed in the UK for type 2 diabetes and weight management. As with any medication affecting metabolic pathways, patients and clinicians have raised concerns about potential effects on mental health. Does Mounjaro cause depression or anxiety? Understanding the current evidence, recognising symptoms, and knowing when to seek help are essential for anyone taking this medication. This article examines the clinical data, explores confounding factors, and provides practical guidance for monitoring mental wellbeing whilst using Mounjaro.

What Is Mounjaro and How Does It Work?

Mounjaro (tirzepatide) is a prescription medicine licensed in the UK for the treatment of type 2 diabetes mellitus and, more recently, for weight management in adults with obesity (BMI ≥30 kg/m²) or overweight (BMI ≥27 kg/m²) with at least one weight-related comorbidity. NHS availability is subject to NICE technology appraisal criteria and local commissioning decisions. It is administered as a once-weekly subcutaneous injection and represents a novel class of medication known as a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist.

The mechanism of action involves mimicking two naturally occurring incretin hormones that regulate blood glucose and appetite. By activating GIP and GLP-1 receptors, Mounjaro enhances insulin secretion in response to meals, suppresses glucagon release (which reduces glucose production by the liver), slows gastric emptying, and promotes satiety. These combined effects lead to improved glycaemic control and significant weight reduction in many patients.

Mounjaro is typically initiated at a low dose (2.5 mg weekly) for tolerability and gradually increased over several weeks to minimise gastrointestinal side effects, which are the most commonly reported adverse reactions. Therapeutic doses start from 5 mg weekly, with maximum doses reaching 15 mg weekly depending on individual response and tolerability.

Hypoglycaemia is uncommon when Mounjaro is used alone, but the risk increases when combined with insulin or sulfonylureas. If you take these medications, your doctor may need to adjust their doses.

As with any medication affecting metabolic and hormonal pathways, questions naturally arise about potential effects on mental health. Patients and healthcare professionals have raised concerns about whether Mounjaro might influence mood, anxiety levels, or contribute to depressive symptoms. Understanding the evidence base and recognising any changes in mental wellbeing whilst taking this medication is essential for safe and effective treatment.

Clinical Evidence on Mounjaro and Mental Health

The relationship between Mounjaro and mental health symptoms such as depression or anxiety remains an area of ongoing scrutiny. Current clinical trial data from the pivotal SURPASS programme (which evaluated tirzepatide for type 2 diabetes) and the SURMOUNT trials (assessing weight management) do not identify depression or anxiety as common adverse effects directly attributable to the medication. The UK Summary of Product Characteristics (SmPC) for Mounjaro does not list psychiatric disorders as established side effects of tirzepatide.

The Medicines and Healthcare products Regulatory Agency (MHRA) and European Medicines Agency (EMA) have reviewed the wider class of GLP-1 receptor agonists regarding reports of suicidal ideation. Their conclusion to date is that no causal link has been established, though vigilance continues.

There is no official link definitively established between Mounjaro and the development of depression or anxiety. Post-marketing surveillance continues to monitor real-world safety data, and regulatory authorities remain vigilant for any emerging signals. Some patients have reported mood changes anecdotally, but causality is difficult to establish given the complex interplay of factors affecting mental health.

Several confounding variables must be considered when evaluating mental health changes in patients taking Mounjaro:

• Pre-existing mental health conditions: Both type 2 diabetes and obesity are independently associated with higher rates of depression and anxiety. Patients may have underlying or undiagnosed mental health concerns prior to starting treatment.

• Lifestyle and body image changes: Rapid weight loss, dietary modifications, and changing body image can trigger psychological responses, both positive and negative.

• Metabolic effects: Significant changes in blood glucose levels, particularly hypoglycaemia (though uncommon with tirzepatide alone), can affect mood and cognitive function.

• Gastrointestinal symptoms: Persistent nausea, vomiting, or other gastrointestinal side effects may contribute to reduced quality of life and secondary mood disturbance.

Healthcare professionals should maintain a balanced perspective, acknowledging patient concerns whilst emphasising that robust evidence for a direct causal relationship remains limited. Continued monitoring and open communication are essential components of safe prescribing practice.

Recognising Mental Health Changes While Taking Mounjaro

Patients taking Mounjaro should be aware of potential changes in their mental wellbeing and know how to recognise symptoms that warrant attention. Early identification of mood disturbances enables timely intervention and appropriate support.

Key symptoms of depression to monitor include:

• Persistent low mood or sadness lasting more than two weeks

• Loss of interest or pleasure in activities previously enjoyed

• Significant changes in appetite or sleep patterns (beyond those expected from the medication's effects on satiety)

• Fatigue, low energy, or feeling slowed down

• Difficulty concentrating or making decisions

• Feelings of worthlessness, excessive guilt, or hopelessness

• Recurrent thoughts of death or self-harm

Signs of anxiety that may develop or worsen include:

• Excessive worry that is difficult to control

• Restlessness or feeling on edge

• Physical symptoms such as rapid heartbeat, sweating, trembling, or shortness of breath

• Sleep disturbance related to worry or rumination

• Avoidance of situations due to fear or apprehension

• Panic attacks (sudden episodes of intense fear with physical symptoms)

It is important to distinguish between temporary adjustment reactions—which may occur as patients adapt to medication, lifestyle changes, or weight loss—and more persistent or severe mental health symptoms requiring professional assessment. Keeping a simple mood diary or using validated screening tools such as the PHQ-9 (for depression) or GAD-7 (for anxiety) can help track changes over time. These are screening tools, not diagnostic instruments, and results should be discussed with a healthcare professional.

If you take insulin or sulfonylureas alongside Mounjaro, consider keeping a combined mood and blood glucose diary, as hypoglycaemia can sometimes mimic or trigger anxiety symptoms.

Patients should also be mindful that mental health symptoms may emerge gradually rather than suddenly, and family members or close contacts may notice changes before the individual does. Open communication with loved ones can provide valuable perspective and support.

For more information about depression and anxiety symptoms, visit the NHS website pages on depression and anxiety disorders.

What to Do If You Experience Depression or Anxiety on Mounjaro

If you develop symptoms of depression or anxiety whilst taking Mounjaro, prompt action and communication with healthcare professionals are essential. Do not stop taking your medication abruptly without medical guidance, as this may affect your diabetes control or weight management progress.

Immediate steps to take:

• Contact your GP or prescribing clinician to discuss your symptoms. Be specific about when symptoms started, their severity, and any potential triggers or patterns you have noticed.

• Seek urgent help if you experience thoughts of self-harm or suicide. Call 999 or go to A&E immediately if you are in immediate danger. Otherwise, contact your GP, call NHS 111, or use NHS urgent mental health helplines. The Samaritans (116 123) provide 24-hour confidential support.

• Keep taking your medication unless specifically advised otherwise by a healthcare professional. Stopping suddenly may cause rebound effects on blood glucose or appetite regulation.

• If you take insulin or sulfonylureas, check your blood glucose levels when experiencing mood changes, as hypoglycaemia can affect mood and anxiety levels.

Your healthcare team will likely:

• Conduct a thorough assessment of your mental health symptoms, including severity, duration, and impact on daily functioning

• Review your complete medication list to identify any potential drug interactions or contributing factors

• Evaluate whether symptoms may be related to metabolic changes, such as hypoglycaemia or rapid weight loss

• Consider whether pre-existing mental health conditions may have been exacerbated

• Discuss the risks and benefits of continuing Mounjaro versus alternative treatment options

Management options may include:

• Continuing Mounjaro with enhanced monitoring if symptoms are mild and other contributing factors are identified

• Psychological support such as cognitive behavioural therapy (CBT) or counselling through NHS Talking Therapies (self-referral is possible in many areas)

• Antidepressant or anxiolytic medication if clinically indicated, prescribed alongside Mounjaro with appropriate monitoring

• Dose adjustment or temporary discontinuation of Mounjaro if symptoms are severe or a clear temporal relationship is established

• Referral to specialist services such as mental health teams or endocrinology for complex cases

Maintaining regular follow-up appointments is crucial for monitoring both your physical and mental health. Be honest about your symptoms and any concerns—your healthcare team can only provide appropriate support if they have complete information about your wellbeing.

If you suspect Mounjaro may be contributing to mood changes or other side effects, report this through the MHRA Yellow Card scheme (www.mhra.gov.uk/yellowcard), which helps authorities monitor medication safety.

Frequently Asked Questions