Ozempic Brain Fog: What Is It And Why Does It Occur?

Ozempic is a modern glucagon-like peptide 1 (GLP-1) agonist that is used for managing blood sugar in type 2 diabetes and weight loss. Recent media coverage has picked up on symptoms of ‘brain fog’ that have been reported from numerous patients. This article covers some of the common causes and explanations of Ozempic brain fog and outlines some suggestions of what to do to get rid of Ozempic brain fog.
Klara Hatinova

Klara Hatinova

Klara is postgraduate researcher in experimental psychology at the
University of Oxford.

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What Is Ozempic?

Ozempic is a popular medication used to manage type 2 diabetes in patients who cannot take metformin, the most common treatment for type 2 diabetes [1]. It contains the active ingredient semaglutide, which can be injected once a week under the skin.

How Does Ozempic Work?

Ozempic is a peptide marketed by Novo Nordisk used for weight loss that stimulates the effects of the endogenous hormone glucagon-like peptide 1 (GLP-1). By mimicking GLP-1's actions, Ozempic increases insulin release from the pancreas, which keeps blood sugar in a healthy range. Furthermore, GLP-1 receptors are also found throughout the brain, most notably in the hypothalamus, the regulator of satiety in the brain and homeostatic functions like breathing, water retention, and sleep [2].

GLP-1 is also considered to regulate the stress response, which will be important in understanding Ozempic brain fog. Notably, Ozempic, with the active ingredient semaglutide, works similarly to other GLP-1 receptor agonists, including dulaglutide, liraglutide and exenatide. This means that many of the effects of Ozempic brain fog can be generalized to other GLP-1 medications [3].

Ozempic Brain Fog: What Does It Mean?

Recently, the Daily Mail published an article discussing the phenomenon of Ozempic brain fog. The article discusses a type of depression, anhedonia, and loss of interest in activities people previously found rewarding [4]. The authors even claim that Ozempics change people’s personalities.

Ozempic brain refers to symptoms of hypoglycaemia, or low blood glucose, which can be experienced when you have enhanced insulin release or reduce body weight. Other causes of Ozempic brain fog are psychological and relate to changes in reward processing.


Symptoms of Ozempic Brain Fog

There are several key mental health symptoms of Ozempic brain fog:

  • reduced libido
  • reduced pleasure from sex
  • reduced pleasure from drinking alcohol or dramatically ameliorated alcohol cravings
  • reduced tendency to splurge in shops
  • dulled emotions
  • suicidailty (in extreme cases, although this claim is not directly supported by the European Drug Agency [1])

Amongst these psychological effects of Ozempic brain fog, there are critical physiological symptoms of brain fog that a rapid weight loss may cause. These include:

  • dizziness
  • inability to focus
  • distractability
  • feeling faint or like you don’t have enough energy

Potential Explanations of Ozempic Brain Fog

Your Blood Sugar Is Too Low

The most likely reason you are experiencing brain fog is that your blood sugar is too low. This can cause the physical symptoms outlined above, including dizziness, sweating, hunger, and an inability to focus [5]. Ozempic increases the amount of insulin released, which lowers blood sugar.


Low blood sugar on Ozempic may be exacerbated if you are taking Ozempic as a combination therapy, for example with insulin injections, or sulfonylureas such as glipizide, glyburide or glimepiride [5].

Changed Neurobiology of Reward

There is a second prevailing hypothesis of what causes psychological Ozempic brain fog. This is linked to the neural processes of reward through liking and motivation. These overlapping circuits in the brain have critically influenced human evolution.

Liking is the hedonic process through which one experiences pleasure, for example, after eating high sugar – high-fat foods, during sex or when treating yourself to purchased items. Motivation is very similar but refers to the effort you are willing to expend to obtain something you like.

Liking is the hedonic process through which one experiences pleasure, for example, after eating high sugar – high-fat foods, during sex or when treating yourself to purchased items.

Notably, the hypothalamus plays a central role in regulating liking and motivation. It is hypothesized that GLP-1 agonists like Ozempic help you lose weight by reducing the pleasure you experience from highly palatable foods, making you less motivated to seek them out. Nonetheless, this reduced motivation and liking can transfer to other areas of your life, including shopping, drinking, social activities, or sex. Hence, Ozempic brain fog can also be referred to as a type of apathy, which is common in psychiatric disorders like depression or neurological conditions like Parkinson’s Disease.

What Should I Do If I Experience Ozempic Brain Fog?

If you are experiencing the symptoms of Ozempic brain fog, it is important to note specific occasions on which this occurs. You may find it helpful to consult with a close friend or family member, as they may be able to provide an external perspective on your behaviour and identify any changes.

If you think you may have low blood sugar, consider taking a shot of fruit juice, a sugar cube, or some full-sugar soda. If your brain fog clears after this, consult your healthcare provider to avoid further hypoglycemic episodes.

The next step is to carefully evaluate whether the indication for which you have been prescribed Ozempic is more disruptive to your daily activities than Ozempic brain fog. Talking to a healthcare professional will be critical in making an informed decision. If you find that Ozempic is not the correct medication for you, there are other medications for type 2 diabetes and weight loss, such as phentermine, your healthcare professional may suggest.

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Klara Hatinova

Klara Hatinova

Klara is a postgraduate researcher in experimental psychology at the University of Oxford. She has worked across a spectrum of hot topics in neuroscience, including her current project measuring reinforcement learning strategies in Parkinson’s disease. Previously, she studied the efficacy of psilocybin as a therapy for critical mental health conditions and examined molecular circadian rhythms of migraine disorders. She completed her undergraduate degree in Neuroscience at the University of Glasgow and participated in a year abroad at the University of California, where she worked on a clinical trial for spinal cord injury.