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Prescription weight loss that puts you first

Glucagon-like peptide-1 receptor agonists (GLP-1s) like Ozempic® (semaglutide) and Wegovy® (semaglutide) have gained popularity for their effectiveness in supporting blood sugar control in those with diabetes and weight loss in those with obesity.
With more people using weight loss drugs with the active ingredient semaglutide, there are more conversations about individual experiences. For instance, more people are comparing notes about potential side effects like brain fog.
Does using Ozempic cause brain fog? We took a closer look at what’s going on with Ozempic users reporting brain fog, including how the medication works in the brain and what the drug packaging says about side effects.
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If you’re on social media platforms like TikTok and Reddit, you may have seen trending conversations about Ozempic and brain fog.
Some Ozempic users describe the experience as going “into a zombie state” or feeling “groggy and forgetful,” which they say can last for a few weeks or a few months depending on the person.
While reports should be taken seriously, the majority of evidence behind the relationship between taking Ozempic and experiencing brain fog is anecdotal.
It’s difficult to investigate the science behind what may be happening because research on this topic is lacking.
We looked into some of the reasons why this could be happening.
GLP-1s affect the brain's reward center by influencing the activity of neurotransmitters and signaling pathways involved in appetite regulation.
They interact with GLP-1 receptors in key regions of your brain, including the hypothalamus and the mesolimbic system, which are crucial for hunger and reward processing.
Here, GLP-1s help regulate energy balance by promoting satiety, which can lead to less food intake.
This, in turn, helps reduce cravings and the desire to eat, ultimately reducing calorie intake and supporting weight loss.
While we may not have scientific evidence about brain fog specifically, there are other documented brain-related side effects of using Ozempic.
While some people experience antidepressant effects, some have reported the opposite. There are concerns about the risk of depression, anxiety, and suicidal thoughts linked to these weight loss medications. More research on mental health effects is needed.
On the other hand, emerging research suggests GLP-1s may offer protective benefits for your brain. For example, some limited research suggests using GLP-1s may help prevent cognitive decline and neurodegenerative conditions like dementia in certain populations.
The phrase “food noise” refers to constant intrusive thoughts about food and constant food cravings. People who experience food noise report feeling extremely preoccupied with thoughts about eating, meals, snacks, and specific foods, even when they're not particularly hungry.
In the context of food noise, this kind of mental distraction can lead to overeating, making poor food choices, or difficulty resisting ongoing urges to eat certain things.
Many people report regularly experiencing food noise, which can be a significant barrier to any weight loss journey. People who are trying to lose weight are especially excited about Ozempic for this reason: GLP-1s like Ozempic can help reduce food noise by acting on your brain’s appetite and reward centers.
Interestingly, one study even found that GLP-1s can have anti-addiction effects related to drug, alcohol, and tobacco use disorders.
These mechanisms are not yet well understood, but researchers think they could involve how GLP-1s influence the signaling of dopamine, a brain chemical involved in feelings of motivation, pleasure, and satisfaction. This could also be relevant to food cravings.
While Ozempic can be very effective for weight loss, especially when combined with other lifestyle habits like good nutrition and exercise, not everyone responds how they hope. Also, it’s important to note that Ozempic isn’t specifically FDA-approved for weight loss, but healthcare providers can prescribe it off-label for this purpose at their discretion.
Ozempic has potential side effects that are important to know about before using it.
Extensive studies demonstrate that most semaglutide side effects are mild, temporary, and related to the digestive system. And according to the Food and Drug Administration Ozempic package insert, the most common side effects of Ozempic — reported in five percent or more of users — are nausea, vomiting, diarrhea, abdominal pain, and constipation.
Others can include:
Reduced appetite
Fatigue
Dizziness
Headache
Acid reflux
Injection site reactions (redness, swelling, or itching)
More serious and rare potential side effects may also occur. These include:
Pancreatitis (inflammation of the pancreas)
Hypoglycemia (especially when used with other diabetes medications)
Kidney problems, including acute kidney injury
Gallbladder disease, including gallstones
Allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing)
Ozempic may also increase the risk of thyroid tumors called medullary thyroid carcinoma. Additionally, there’s a possibility that people who have diabetic eye disease will have a higher risk of diabetic retinopathy complications on this drug.
Because discussions about Ozempic and brain fog are fairly common, we rounded up some related FAQs.
Ozempic may affect your mood. While its primary function is to manage blood sugar levels, some people report mood changes, like feelings of anxiousness or depression.
This may be due to the medication's effects on the central nervous system or as a secondary result of changes in diet and weight. More research is needed to better understand the connection between Ozempic and mental health.
There’s no strong evidence to suggest that Ozempic causes memory loss. While GLP-1s primarily target blood sugar regulation and appetite control, their effects on brain function are still being studied.
Some research even indicates they may offer protective benefits for the brain, which could positively impact memory and cognitive health rather than impair it. We know we sound like a broken record here, but more research is needed.
Ozempic is considered safe for most people when used as prescribed, but it has potential side effects. It’s important to use Ozempic under the supervision of a healthcare professional and alert them if you experience anything unexpected.
Ozempic is active in the brain. Brain-related side effects are possible, considering GLP-1s target the brain reward pathways.
There are other options. If you’re using Ozempic and experience brain fog or related side effects that are concerning to you, know that you can try something else. In addition to healthy lifestyle habits like nutrition and movement, you can discuss other weight loss medications with your healthcare provider.
Mental health matters. Regardless of whether you’re experiencing brain fog from using Ozempic, if your mood is suffering we encourage finding a therapist. Getting the mental health support you need is essential for your weight loss success and overall quality of life.
Are you interested in connecting with one of Hers’ affiliated licensed medical providers? We’d love to help! Start by taking our free online weight loss assessment.
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This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.
Bachelor of Arts, Egyptian and Ancient Western Asian Archaeology - Brown University | College, 2011
Doctor of Medicine - Brown University | Warren Alpert Medical School, 2017
Master of Public Health - Columbia University | Mailman School of Public Health, 2018
Master of Liberal Arts, Journalism - Harvard University | Harvard Extension School, 2022
Master of Science, Healthcare Leadership - Cornell University | Weill Cornell Graduate School of Medical Sciences, 2024
Master of Business Administration - Cornell University | Samuel Curtis Johnson Graduate School of Management, 2024
Internship - NYU Grossman School of Medicine | Internal Medicine Residency—Community Health Track, 2019
New York, 2019
Certified in Public Health - National Board of Public Health Examiners, 2018
Medical Writer Certified - American Medical Writers Association, 2020
Editor in the Life Sciences - Board of Editors in the Life Sciences, 2020
Certified Personal Trainer - National Academy of Sports Medicine, 2022
Certified Nutrition Coach - National Academy of Sports Medicine, 2023
Board Certified Medical Affairs Specialist - Accreditation Council for Medical Affairs, 2023
Certificate of Advanced Education in Obesity Medicine - Obesity Medicine Association, 2025
Regulatory Affairs Certification - Regulatory Affairs Professionals Society, 2025
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Medical Expert Board Member - Eat This, Not That!, 2021–
Director Scientific & Medical Content - Beren Therapeutics P.B.C., 2023–2024
Director, Medical Content & Education - Ro, 2021–2023
Associate Director, Medical Content & Education - Ro, 2020–2021
Senior Medical Writer - Ro, 2019–2020
Medical Editor/Writer - Sharecare, 2017–2020
Medical Student Producer - The Dr. Oz Show, 2015–2016
Research Affiliate - University Hospitals of Cleveland, 2013–2014
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The Dr. Oz Show: Behind-the-scenes contributor to Emmy Award-winning health segments
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Dr. Bohl developed a passion for medical content while working at The Dr. Oz Show. He realized that, through the media, he could bring important health information to the lives of many more people than he would be able to working in a doctor’s office.
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