GLP-1 medicines and anxiety: what the research actually shows

What the randomised trials show

Semaglutide, the STEP trials. A 2024 analysis in JAMA Internal Medicine pooled the STEP 1, 2, 3 and 5 trials of semaglutide 2.4 mg, in people without major psychiatric illness. Depression scores at week 68 were very slightly better on semaglutide than placebo, and people on semaglutide were less likely to move into a more severe depression category. Suicidal thoughts or behaviour were reported by 1% or fewer, with no difference between the groups. Psychiatric side effects were generally balanced.

The European regulator's review. In April 2024, the European Medicines Agency's safety committee concluded that the available evidence does not support a causal link between GLP-1 medicines, including semaglutide, and suicidal or self-injurious thoughts and actions.

Two limits matter. The STEP analysis was of depression and suicidality, not anxiety disorders specifically, and it excluded people with major psychiatric illness.

What the record studies show

Studies of health records look at far more people in everyday care, but cannot prove that a medicine caused what followed. Their results differ.

• Higher risk, South Korea. A 2026 study of records from 13 hospitals compared 2,357 people who started semaglutide for weight loss with matched people who did not. Those on semaglutide were diagnosed with an anxiety disorder at about 2.4 times the rate, and a depressive disorder at about 3.4 times, though the margins of uncertainty were wide. Liraglutide showed similar, smaller increases. The authors called for careful patient selection and monitoring.
• No change, Australia. A 2026 study of 666 adults with severe obesity in a Sydney weight management programme found no significant change in scores for depression, anxiety, stress or eating disorder risk over 12 months in the 31 people who started a GLP-1 medicine. It was small.
• Mostly stable, United States. A 2026 review of the records of 226 people on GLP-1 medicines found that most people's existing anxiety or depression stayed stable, but new or worsening symptoms appeared in a minority.

Record studies are open to other explanations. People starting a weight-loss medicine may already differ from those who do not, and people who see a doctor more often are more likely to have any diagnosis recorded. But a finding like the Korean one is exactly why it is worth paying attention to your mood.

Why some people feel calmer

We could find no trial that measured calmness directly. The 2025 joint advisory notes that many people who lose weight on these medicines experience improved mood. What trials do show is less food craving and better control of eating on semaglutide, and less craving and less reaction to food on tirzepatide. A small 2025 trial also found low starting doses of semaglutide reduced alcohol craving in people with alcohol use disorder. For someone who has spent years fighting constant thoughts about food, that change alone can feel like quiet. (See food noise and microdosing for a calmer mind.)

Why some people feel worse

• Low blood sugar. The NHS lists feeling anxious or irritable, sweating, shaking and heart palpitations among its symptoms. It says low blood sugar is rare in people without diabetes and usually affects people who take insulin or some other diabetes medicines.
• Side effects. Nausea and poor sleep wear anyone down. (See nausea on a GLP-1 and sleep.)
• Long gaps without food. A 2025 joint advisory from four US nutrition and obesity medicine societies notes that less interest in food can lead people to go several hours without eating, and advises regular, small meals at consistent times rather than becoming overly hungry.
• Losing the comfort of food. The same advisory notes that frustration, or a loss of the pleasure food used to bring, can change mood for some people. A 2026 European consensus statement on these medicines describes psychological and identity-related challenges, including shifts in food reward and coping, and recommends psychological screening, with support where needed.

What to do

1. Before starting, tell your prescriber if you have had anxiety, depression or an eating disorder, so they can plan how to keep an eye on it.
2. Notice changes in the first months and after dose increases, and write them down.
3. Eat regularly, with protein, rather than going for long stretches without food. (See still hungry on a GLP-1.)
4. If you take insulin or another diabetes medicine, check your blood sugar when you feel anxious or shaky, and tell your prescriber.
5. Low mood or thoughts of suicide or self-harm need help now. Use the numbers below and tell your prescriber straight away. The joint advisory says people should be screened and monitored for mood disorders and suicidal thoughts, and that GLP-1 medicines should be stopped if those symptoms develop.
6. For other anxiety, do not stop or change your dose on your own, but do talk to your prescriber promptly if it is new, persistent or severe.

If you need urgent help, in England call NHS 111 and choose the mental health option, or ask for an urgent GP appointment. Samaritans are available on 116 123. If someone's life is at risk, call 999 or go to A&E. Outside the UK, call your local emergency number.

What to do with this

When your mind is loud, a plan for eating takes one decision off the list. The calculator works out your protein floor and calorie target, so regular meals have a shape.

Get your numbers

Sources

1. Wadden TA, et al. Psychiatric Safety of Semaglutide for Weight Management in People Without Known Major Psychopathology: Post Hoc Analysis of the STEP 1, 2, 3, and 5 Trials. JAMA Intern Med 2024. PubMed
2. European Medicines Agency. Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 8-11 April 2024. ema.europa.eu
3. Park J, et al. GLP-1 Receptor Agonists for Weight Loss and Risk of Major Safety Outcomes: A Multicentre Cohort Study. Diabetes Obes Metab 2026. PubMed
4. Maynard S, et al. Effects of GLP-1 Receptor Agonist Therapy on Eating Disorder Risk and Psychological Distress in Adults With Class 3 Obesity. Int J Eat Disord 2026. PubMed
5. Sa B, et al. Retrospective chart review on psychiatric manifestations of GLP-1 agonist usage. J Psychiatr Res 2026. PubMed
6. Friedrichsen M, et al. The effect of semaglutide 2.4 mg once weekly on energy intake, appetite, control of eating, and gastric emptying in adults with obesity. Diabetes Obes Metab 2021. PubMed
7. Martin CK, et al. Tirzepatide on ingestive behavior in adults with overweight or obesity: a randomized 6-week phase 1 trial. Nat Med 2025. PubMed
8. Hendershot CS, et al. Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial. JAMA Psychiatry 2025. PubMed
9. Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory. Obesity Pillars 2025. PubMed
10. Dobbie LJ, et al. Nutritional, functional, and psychological considerations for incretin-based therapies in adults: an EASO, EFAD, and ECPO Consensus Statement. Lancet Diabetes Endocrinol 2026. PubMed
11. NHS. Low blood sugar (hypoglycaemia). nhs.uk
12. NHS. Where to get urgent help for mental health. nhs.uk

Medical disclaimer: Articles in the foodose research library are educational, not medical advice. If you are in crisis, contact NHS 111, Samaritans on 116 123, or your local emergency number now. See our full medical disclaimer.