Does metoprolol affect brain function?

October 10, 2025 •

4 min read

Beta-blockers are among the top prescribed cardiovascular drugs for the elderly [1.2.2]. As a commonly used beta-blocker, a key question for many patients is: does metoprolol affect brain function? This article explores the nuanced relationship between metoprolol and cognition.

Quick Summary

Metoprolol can affect brain function due to its ability to cross the blood-brain barrier. Effects may include memory issues, sleep disturbances, and mood changes, although research findings are mixed and side effects vary by individual.

Key Points

Lipophilicity Matters: Metoprolol is moderately lipophilic, allowing it to cross the blood-brain barrier and potentially affect CNS function [1.4.1].
Cognitive Effects are Possible: Some patients report memory issues, confusion, and 'brain fog', though research findings on memory impairment are mixed [1.2.1, 1.2.3].
Sleep is Often Disturbed: A common side effect is sleep disturbance, including nightmares and frequent awakenings, which can impact daytime alertness [1.2.3, 1.3.1].
Depression Link is Controversial: While listed as a side effect, large-scale analyses have not found a definitive causal link between beta-blocker use and depression [1.5.3, 1.5.7].
Elderly are More Susceptible: Older adults and those with prior cognitive deficits are at a higher risk for experiencing CNS side effects from metoprolol [1.2.2, 1.4.1].
Alternatives Exist: Hydrophilic beta-blockers, like atenolol, have a much lower risk of causing CNS side effects because they don't cross the blood-brain barrier as easily [1.6.2, 1.6.4].
Consult a Doctor: Any concerning cognitive or mood changes should be discussed with a healthcare provider, who may adjust the dosage or medication [1.7.2].

Understanding Metoprolol and Its Primary Function

Metoprolol is a widely prescribed beta-blocker used to manage a variety of cardiovascular conditions, including hypertension (high blood pressure), angina (chest pain), heart failure, and arrhythmias [1.2.8, 1.3.4]. It belongs to a class of drugs that work by blocking the effects of the hormone epinephrine, also known as adrenaline [1.4.2]. This action helps the heart to beat more slowly and with less force, thereby reducing blood pressure and the heart's workload [1.2.8]. Metoprolol is available in immediate-release (metoprolol tartrate) and extended-release (metoprolol succinate) forms [1.2.5]. While highly effective for heart-related issues, its impact on the central nervous system (CNS) is a subject of ongoing discussion and research.

The Blood-Brain Barrier and Metoprolol's Lipophilicity

The central question of how metoprolol affects brain function hinges on a concept called lipophilicity. Lipophilic (fat-soluble) drugs can cross the blood-brain barrier (BBB) more easily than hydrophilic (water-soluble) drugs [1.4.1, 1.4.3]. Metoprolol is classified as a moderately lipophilic beta-blocker [1.4.1, 1.4.4]. This characteristic allows it to penetrate brain tissue at concentrations significantly higher than more hydrophilic beta-blockers like atenolol [1.4.4, 1.6.4]. Its ability to enter the CNS is the primary mechanism through which it can potentially exert effects on brain function, leading to various neurological and psychological side effects [1.4.1].

Potential Cognitive and Psychological Effects

Once in the brain, beta-blockers can influence neurotransmitter systems, which may lead to a range of side effects. While many patients take metoprolol without issue, some report CNS-related symptoms.

Cognitive Function: Memory, Concentration, and 'Brain Fog'

The evidence regarding metoprolol's impact on cognitive functions like memory and concentration is mixed. Some studies and patient reports link metoprolol to memory lapses, difficulty concentrating, confusion, and general 'brain fog' [1.2.1, 1.2.4, 1.2.6]. Memory loss is listed as a rare or uncommon side effect [1.2.4, 1.2.5]. One recent study highlighted that metoprolol can exacerbate cognitive decline, particularly in elderly patients, potentially through mechanisms like oxidative stress and neuroinflammation [1.2.2]. However, other controlled studies have found no significant impact on memory performance in healthy volunteers at standard doses [1.2.3, 1.3.1]. This discrepancy suggests that effects may be more pronounced in older individuals or those with pre-existing cognitive deficits [1.2.2, 1.3.8].

Psychological and Mood Effects: Depression and Anxiety

The link between beta-blockers and depression has been debated for years. Depression is listed as a common side effect of metoprolol [1.2.4, 1.2.5]. Some studies suggest an association, noting that lipophilic beta-blockers like metoprolol carry a higher risk of depression than hydrophilic ones [1.5.5]. The use of metoprolol can be controversial in patients with pre-existing depression or anxiety, as it may worsen symptoms [1.5.1, 1.5.4].

Conversely, a large-scale meta-analysis from 2021 concluded that there is no significant association between beta-blocker therapy and depression [1.5.3, 1.5.7]. That analysis found that while fatigue was a common reason for discontinuing the medication, depression was not more common in patients taking beta-blockers compared to a placebo [1.5.7]. This suggests that while individuals may experience mood changes, it may not be a widespread, direct pharmacological effect for the majority of users.

Sleep Disturbances and Hallucinations

A more consistently reported side effect is sleep disturbance. Metoprolol has been shown to cause more frequent awakenings, nightmares, and vivid dreams [1.2.3, 1.2.6, 1.3.1]. These sleep issues can indirectly affect cognitive function during the day, contributing to feelings of fatigue and poor concentration [1.2.3]. In rare cases, metoprolol has been linked to more severe neuropsychiatric effects, including visual hallucinations, delirium, and psychosis, particularly in elderly patients [1.2.7, 1.3.3, 1.3.4, 1.3.6]. These events are typically reversible upon discontinuation of the drug [1.3.4].

Comparison of Beta-Blockers: Lipophilic vs. Hydrophilic

Not all beta-blockers are the same. The likelihood of CNS side effects is strongly tied to whether the drug is lipophilic or hydrophilic.


Feature	Lipophilic Beta-Blockers (e.g., Metoprolol, Propranolol)	Hydrophilic Beta-Blockers (e.g., Atenolol)
Blood-Brain Barrier Crossing	High to moderate; readily enters the CNS [1.6.4]	Low; limited entry into the CNS [1.6.4]
Metabolism	Metabolized by the liver [1.4.4, 1.6.1]	Excreted by the kidneys [1.4.4]
Potential for CNS Side Effects	Higher risk of sleep disturbances, fatigue, confusion, depression, and hallucinations [1.6.1, 1.6.2]	Lower risk of CNS side effects [1.6.2, 1.6.4]
Brain Concentration	Brain/plasma concentration ratio is about 12 for metoprolol [1.4.5]	Brain/plasma concentration ratio is about 0.2 for atenolol [1.4.5]

Switching from a lipophilic agent like metoprolol to a hydrophilic one like atenolol can often resolve CNS side effects such as hallucinations or nightmares [1.2.7, 1.3.4].

Conclusion: A Nuanced Relationship

So, does metoprolol affect brain function? The answer is yes, it can, due to its ability to cross the blood-brain barrier. The most commonly reported effects are sleep disturbances, fatigue, and dizziness [1.2.5]. More significant cognitive effects like memory loss and depression are reported less frequently and the evidence is conflicting, with some large studies showing no link to depression [1.5.3]. The risk of these side effects appears to be higher in the elderly and those with pre-existing cognitive issues [1.2.2, 1.4.1]. These effects are often dose-dependent and can sometimes be managed by lowering the dose or switching to a more hydrophilic beta-blocker [1.7.1, 1.7.2]. Patients experiencing concerning cognitive or psychological changes should always consult their healthcare provider.

For more information on beta-blocker properties, a useful resource is the British Heart Foundation. https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/beta-blockers

Frequently Asked Questions

Memory loss is considered a rare or uncommon side effect of metoprolol [1.2.4, 1.2.5]. While some patients report memory lapses, some clinical studies have not found a significant impact on memory [1.2.3]. The risk may be higher in elderly patients [1.2.2].

Yes, some patients on metoprolol report experiencing cognitive side effects that can be described as 'brain fog,' including issues with memory and concentration [1.2.1]. This may be related to the drug's effect on the central nervous system.

Hydrophilic (water-soluble) beta-blockers, such as atenolol, cross the blood-brain barrier to a much lesser extent than lipophilic ones like metoprolol [1.6.4]. This results in a significantly lower risk of central nervous system side effects [1.6.2].

The connection is controversial. While depression is listed as a potential side effect and some studies show an association, a major 2021 meta-analysis found that beta-blockers were not more likely to cause depression than a placebo [1.2.4, 1.5.3, 1.5.7].

Yes, sleep disturbances are one of the more consistently reported CNS side effects of metoprolol. These can include difficulty sleeping through the night, vivid dreams, and nightmares [1.2.3, 1.2.6].

Generally, no. Most central nervous system side effects, such as confusion, hallucinations, or mood changes, tend to resolve within a few days to a week after discontinuing the medication or switching to a different type [1.2.7, 1.3.4].

You should talk to your doctor right away. Do not stop taking the medication suddenly, as this can be dangerous [1.2.8]. Your doctor can assess your symptoms and may recommend adjusting the dose or switching to an alternative medication with fewer CNS effects [1.7.2].