Low mood associated with GLP-1 medications

How do GLP-1 medications work?

GLP-1 receptor agonists mimic the action of glucagon-like peptide-1, a hormone released by the intestine after eating.

They support weight loss through several mechanisms, including:

• Reducing appetite by acting on areas of the brain involved in hunger regulation
• Increasing feelings of fullness after meals
• Slowing gastric emptying, allowing food to remain in the stomach for longer
• Improving blood glucose control by stimulating insulin release when blood sugar levels rise
• Reducing glucagon secretion, helping to limit glucose production by the liver

Together, these effects help reduce calorie intake and support sustainable weight loss when combined with healthy lifestyle changes.

Can GLP-1 medications cause low moods?

Some patients have reported experiencing low mood or changes in emotional wellbeing while taking GLP-1 medications. However, reports alone do not establish that the medication is the direct cause of these symptoms.

In 2024, the Medicines and Healthcare products Regulatory Agency (MHRA) completed a review of available safety data following reports of depression, suicidal thoughts and self harm in people taking GLP-1 receptor agonists. [1]

The review included:

• UK Yellow Card reports
• Clinical trial data
• Published scientific literature
• Observational studies
• International pharmacovigilance data

The MHRA concluded that the available evidence did not show association between GLP-1 receptor agonists and depression, suicidal thoughts or self harm. [1]

Although research continues and medicines are subject to ongoing safety monitoring, current evidence remains reassuring.

Why might low mood occur during treatment?

Low mood experienced during treatment may be influenced by several factors that are unrelated to a direct effect of the medication itself.

Changes in appetite and food

GLP-1 medications reduce appetite and can significantly decrease interest in food. For some individuals, food provides enjoyment or forms part of social interactions. Changes in eating habits may therefore affect emotional wellbeing, particularly during the early stages of treatment.

Lifestyle adjustment

Successful weight loss often involves substantial changes to eating patterns, physical activity and daily routines. Although these changes support better health, adapting to a new lifestyle may be emotionally challenging for some individuals.

Existing mental health conditions

Some patients beginning GLP-1 treatment may already have an underlying mental health condition, making it difficult to determine whether symptoms are related to treatment or reflect the natural course of their condition.

Physical side effects

Common adverse effects such as nausea, vomiting, constipation, diarrhoea and fatigue may temporarily affect overall wellbeing and contribute to reduced mood.

Reduced calorie intake

Significantly reduced food intake, inadequate nutrition or dehydration may contribute to fatigue, irritability and low mood. Maintaining a balanced diet and adequate hydration throughout treatment is important to support both physical and mental wellbeing.

GLP-1 medications and antidepressants

Many people prescribed GLP-1 medications also take antidepressants for depression or anxiety. There is no current evidence to indicate that GLP-1 receptor agonists reduce the effectiveness of antidepressant medication or worsen depression.

GLP-1 medications slow gastric emptying, which may alter the absorption of orally administered medicines. Although this effect has not been shown to reduce the effectiveness of prescribed antidepressants, healthcare professionals may recommend monitoring symptoms when starting or increasing the dose of a GLP-1 medication.

Patients taking antidepressants should continue their medication as prescribed unless advised otherwise by their healthcare professional.

If symptoms of depression or anxiety worsen during treatment, it is recommended you speak to your GP to assess possible contributing factors.

When to Seek Medical Advice

Please contact your GP as soon as possible if you experience:

• Persistent low mood
• Loss of interest in activities they would usually enjoy
• Increasing anxiety or emotional distress
• Significant changes in sleep or concentration
• Mood changes that interfere with daily activities or quality of life

These symptoms should be assessed regardless of whether they are thought to be related to GLP-1 treatment.

Call 999 or go to your Nearest A&E Immediately

• Immediate medical attention should be sought if thoughts of self harm or suicide occur. 

Patients should not discontinue GLP-1 treatment or antidepressant medication without first discussing their symptoms with their prescribing clinician or GP.

Important Safety Advice

It is important to use GLP-1 medications safely and in line with clinical guidance.

Maintaining open communication with your provider is key to ensuring safe and effective treatment.

Remember:

• Do not ignore persistent or worsening symptoms
• Do not increase or stop your medication without advice
• Ensure your GP is informed of any new or unusual symptoms

Additional support

If you are experiencing side effects or have any questions about your treatment, our clinical team is here to help.

If your symptoms are severe, worsening, or you feel they require urgent medical attention, please seek immediate advice from your GP, NHS 111, or attend your nearest A&E department if appropriate.

For all other queries:

• Book a free video consultation with one of our trained clinicians through our website. Appointments are available throughout the week, including daytime and evening sessions.
• Send us your question online using our form: https://forms.medicinemarketplace.com/251345635207050 A member of our clinical team will respond by email.
• Speak to us by phone by calling 0330 175 5747, and selecting option 3.

We are here to answer your questions and provide support throughout your treatment journey.

Reference

[1] MHRA finds evidence does not support a link between Glucagon-Like Peptide-1 (GLP-1) receptor agonists and suicidal and self-injurious thoughts and actions (Accessed: 7 July 2026)  

Written by: Uzma Dala MPharm (2238839)

Approved by: Shameela Adam MPharm (2070113)