Have you noticed changes in your mood or personality since starting a glucagon-like peptide-1 (GLP-1) receptor agonist? Or has someone mentioned that they’re worried GLP-1 drugs could affect your mental health?

These concerns are valid and worth exploring. GLP-1 medications don’t just affect your body — they can also impact how your brain works. It’s important to understand the possible effects on the way you think and feel. With this information, you and your healthcare provider can decide if GLP-1 drugs are right for you.

How Do GLP-1 Drugs Work?

Glucagon-like peptide-1 is a hormone that your body makes to help manage blood glucose (blood sugar) levels and hunger. Cells throughout your body have special spots called receptors that respond to GLP-1. When the hormone binds to these receptors, it tells those cells what to do.

GLP-1 drugs are designed to act like this natural hormone. When you inject the medication, it attaches to the same receptors and triggers similar effects. GLP-1 drugs help your body regulate levels of insulin (a hormone that lets your body use the food you eat for energy) and glucose.

These medications also help slow down how fast your stomach empties and reduce how hungry you feel. Together, these effects may help control appetite and regulate blood sugar. This is why GLP-1 drugs are often used to treat type 2 diabetes, a condition in which the body has a hard time controlling high glucose levels. GLP-1 drugs are also used as weight loss drugs.

GLP-1 receptors are found throughout your body — they’re in your lungs, skin, nerves, cardiovascular (heart and blood vessel) system, and gastrointestinal tract. The receptors are also found in your central nervous system, which includes the brain. Studies show that GLP-1 drugs need to work on the brain to help with weight loss — which means they may change more than just your appetite.

GLP-1 Drugs and Your Brain

Study findings suggest that GLP-1 drugs can affect your brain in several ways. However, it’s important to remember that this is a new area of research. Scientists are still learning just how these drugs work in the brain, and more clinical trials — studies that test the safety and effectiveness of new therapies in humans — are needed to bring more answers.

GLP-1 drugs seem to affect both serotonin and dopamine systems in the brain. Serotonin and dopamine are brain chemicals that help regulate mood, emotion, and motivation. In animal studies, GLP-1 changed how serotonin works in parts of the brain that regulate mood. Some of these studies were done in mice, which share many genetic similarities with humans.

Other studies, mostly in rodents, found that GLP-1 drugs also change dopamine levels in the brain. Together, these findings suggest that these medications have the potential to affect your mood and how you feel day to day.

These changes may also impact how your brain reacts to rewards. So-called reward pathways get activated every time you do something that feels good, such as eating, drinking alcohol, engaging in substance use, or having sex. Over time, this effect could change how you feel or act.

Effects of GLP-1 Drugs on Mental Health

It’s not yet clear just how GLP-1 drugs are linked to mental health issues and personality changes. However, researchers are starting to see some connections.

People taking these medications are significantly more likely to be diagnosed with mood disorders or experience other mental health issues. These concerns include depression, anxiety, and suicidal ideation (suicidal thoughts).

Note: If you or someone you know needs help, you can contact the 988 Suicide & Crisis Lifeline by calling or texting 988 or chatting online.

The risk of developing these issues may go up the longer a person is on GLP-1 drugs. Taking higher doses may also bring an increased risk of these side effects. These risks vary based on the specific GLP-1 medication being used. However, in general, the longer you take these drugs, the more likely you are to receive a diagnosis related to mental health.

Some researchers caution against overreacting. Even if there is a link with depression and suicidal behavior, it’s rare that people taking GLP-1 drugs experience these serious side effects.

GLP-1 agonists are also tied to an increase in anxious feelings or depressive symptoms, including insomnia, stress, and nervousness, which can affect day-to-day well-being. Some people report changes in how they relate to food that may be linked to eating disorders. These behaviors may include bingeing (episodes of overeating) and fear of overeating.

Researchers also note that these side effects may be more likely to affect people who already have a mental health diagnosis. If further research shows that this is true, that knowledge could help doctors better understand who might benefit from GLP-1 medications, who should be monitored especially closely, and who may want to avoid these drugs.

GLP-1 Medications and Personality or Behavior Changes

Some people taking GLP-1 drugs report behavior or personality changes. In one study that looked at social media posts, people linked these medications with feeling angrier and more erratic. Others said the drugs made it hard to keep up with responsibilities at home, at work, or in relationships.

On the other hand, some people described positive behavior changes, such as no longer participating in addictions and addictive behaviors while taking GLP-1 drugs. These types of experiences show how differently people may respond, and they highlight the need for more research into how GLP-1 medications affect the brain and behavior.

Do You Need Extra Mental Health Monitoring When Using GLP-1s?

Researchers recommend that doctors have a deep understanding of someone’s mental health before that person starts a GLP-1 medication. That way, your care team can better watch for any related symptoms or personality changes — including depression, anxiety, or mood changes. Your doctor should ask questions about your mental health before prescribing a GLP-1 drug.

Some people may need extra check-ins for mental health issues and personality changes. This could mean meeting more often with a healthcare provider or speaking regularly with a licensed therapist or psychiatry specialist.

You and your doctor can work together to determine the right path for you. If you choose to try GLP-1 drugs, they can help you get insurance coverage. If you’re worried about side effects, your doctor can support you — or help you find a different treatment for obesity or weight gain that fits your goals for weight loss and weight management.

If you’re already on a GLP-1 drug and are concerned about personality changes, don’t stop the medication without talking to your doctor first. Be sure to tell them about new or worsening depression, suicidal thoughts, or any unusual changes in mood or behavior. Your doctor can help you find the safest, most effective treatment — and support you in achieving your best quality of life.

Talk With Others Who Understand

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Have you noticed personality changes or depression since starting on GLP-1 drugs? What changes did you see, and how did you handle them? Share your experience in the comments below, start a conversation by posting on your Activities page, or connect with like-minded members in Groups.