Mounjaro® and mood changes

Getting help today

Thoughts of suicide, of self-harm or of not wanting to be alive need help today, not at the next appointment. In the US, call or text 988 or chat at 988lifeline.org, free and confidential at any hour ^[5][12]. You can also call your local emergency number or go to an emergency department; if someone has attempted suicide, call for help right away and do not leave them alone ^[10].

Three regulators, three wordings

Mounjaro® documents handle mood differently by country. The table shows what each says, checked on 20 October 2026.

What the FDA review found

In January 2026 the FDA asked for suicide-risk wording to be removed from the three GLP-1 medicines approved for weight reduction that carried it: Saxenda®, Wegovy® and Zepbound®. It noted that labels for GLP-1 medicines approved for type 2 diabetes, the group that includes Mounjaro®, did not contain that wording ^[5].

Its review combined a meta-analysis of 91 placebo-controlled trials with 107,910 people, which showed no increased risk of suicidal thoughts or behaviour or of anxiety, depression, irritability or psychosis, with a US claims study comparing more than 2.2 million people with type 2 diabetes starting a GLP-1 medicine or an SGLT2 inhibitor. That study found no increased risk of intentional self-harm, including in people with both diabetes and obesity ^[5].

What studies in people with diabetes show

A 2026 analysis of WHO’s global report database, VigiBase, looked only at people with type 2 diabetes. Tirzepatide, semaglutide and liraglutide were reported with depressed mood and suicidal thoughts more often than other diabetes medicines, but there was no signal for suicide attempts or deaths, and absolute report numbers were low. People reporting on GLP-1 medicines were also more likely to have existing depression and to take antidepressants, and adjusting for antidepressants weakened the link. The authors concluded that underlying vulnerability may drive many reports, and suggested watching vulnerable people early in treatment ^[6]. Report databases cannot measure risk.

Records studies give a different view. In 85,546 matched pairs of adults with type 2 diabetes, obesity or both, tirzepatide and semaglutide had similar combined rates of depression, anxiety and suicidal ideation over two years ^[7]. In a US study of people with overweight or obesity, 29% with type 2 diabetes, tirzepatide users had fewer recorded episodes of suicidal ideation or attempts than people on other weight-loss medicines, though the number of events was small ^[8]. Among adolescents, incretin medicines were linked to lower risk of suicide-related events than lifestyle treatment, but not in the subgroup with type 2 diabetes ^[9]. Observational studies cannot prove cause in either direction.

Things on treatment that can affect mood

• Low blood sugar: the Medication Guide lists anxiety, irritability and mood changes among its signs, with shakiness, sweating, hunger and confusion ^[2]. In the US trial of Mounjaro® added to basal insulin, readings below 54 mg/dL occurred in 14% to 19% of people on Mounjaro® and 13% on placebo ^[1].
• Feeling unwell: early nausea, vomiting and diarrhea can wear anyone down. Fatigue was reported by 10% of adults in the long heart-outcomes trial ^[1], and by 2.5% to 4.1% against none on placebo in Canada’s diabetes trial pool ^[4].
• Sleep: MedlinePlus lists sleeping problems among triggers of depression ^[10].
• Living with diabetes: the NIH notes that depression is linked to other health conditions, including diabetes and heart disease ^[11].

Other things that can change mood

MedlinePlus lists stressful life events, social isolation, alcohol or drug use, an underactive thyroid, chronic pain and some medicines, such as steroids and beta-blockers, among factors that can bring on depression, which also runs in families ^[10]. Its list of symptoms includes irritability or anger, withdrawing from others, low energy, hopelessness or guilt, loss of interest in things once enjoyed, sudden appetite changes, trouble concentrating, sleeping too little or too much, and thoughts of death or suicide ^[10].

Several of these overlap with what changes when someone starts a new diabetes or weight treatment. That is why noting what you feel, and when, is more useful than deciding in advance whether the medicine is to blame.

Talking to your clinician

The FDA asks patients to keep taking GLP-1 medicines as prescribed, discuss concerns with their clinician and report new or worsening depression, suicidal thoughts or unusual changes in mood or behaviour ^[5]. Canada asks you to tell your clinician before starting if you have ever had depression or other mental health problems ^[4].

MedlinePlus advises contacting a provider if low mood has affected work, school or family life for more than two weeks, if you have three or more symptoms of depression, or if you think a medicine is making you depressed, and not to stop any medicine without talking to your provider first ^[10]. Family members often notice changes first, and Canada’s wording invites them to speak up ^[4].

Mounjaro® and Zepbound® are registered trademarks of Eli Lilly and Company. Saxenda® and Wegovy® are registered trademarks of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Eli Lilly and Company or Novo Nordisk A/S.