Long COVID Brain Fog: What it is, Why it Happens, and How to Recover - Dr. Michael Ruscio, DC

Does your gut need a reset?

Yes, I'm Ready

Do you want a second opinion?

Yes, I Need Help

Do you want to start feeling better?

Yes, Where Do I Start?

Long COVID Brain Fog: What it is, Why it Happens, and How to Recover

Brain Fog Post COVID Can Be Healed

Key Takeaways:

  • Brain fog is one of the most common symptoms of long COVID, only trailing behind fatigue, sleep issues, and headaches [1, 2, 3]
  • While brain fog can occur with a number of acute and chronic conditions, long COVID brain fog seems to be a little more intense due to neuroinflammation and possible persistence of the original coronavirus infection in the brain and central nervous system [4]
  • Diet intervention, exercise, and supplementation together will likely be required to resolve brain fog and other long COVID symptoms, but recovery is very much possible.

Before the pandemic, “brain fog” wasn’t really a term you heard thrown around in casual conversation. Post-pandemic, it’s pretty unlikely that you’ve managed to avoid the buzz around it, especially related to acute and long COVID infection. 

For a number of reasons, certain people that get coronavirus end up with lingering symptoms, including brain fog, fatigue, dizziness, memory issues, poor concentration, and poor executive function [5, 6, 7]. Brain fog is one of the more common symptoms of long COVID, and only fatigue [1, 2], headaches [2], and sleep issues [3] may be more common. 

In this article, we’ll look into brain fog and long COVID, and what makes it different from other cases of brain fog that come with some autoimmune diseases and other conditions. We’ll also talk about how to improve long COVID brain fog via dietary changes, exercise, and supplementation. 

What is Brain Fog?

Brain fog is characterized by slowed or cloudy thinking, forgetfulness, inability to focus, and poor mental stamina [8]. It’s often associated with gut dysbiosis and leaky gut, chronic inflammation, a dysfunctional immune system, poor thyroid function, hormonal imbalances, and other conditions that cause the body to be thrown off its usual patterns. Personally, I experienced brain fog when I had gut issues, including a parasite infection. Fortunately, I was able to treat the infection, and the brain fog along with my other symptoms resolved.  

With long COVID, brain fog is likely to be caused by the persistence of the initial infection in the central nervous system and neurons, causing neuroinflammation. But it can also be worsened by poor gut health, nutrient deficiencies, low thyroid, and the other conditions listed above. 

Brain fog isn’t unique to COVID infection. Most well-studied infectious diseases caused by viral or bacterial infections have been shown to result in chronic symptoms in a number of patients [4]. 

For example, common viruses such as the Epstein-Barr virus (which causes mononucleosis), cytomegalovirus, enterovirus, and herpesvirus have been linked to chronic fatigue syndrome, which is commonly associated with severe brain fog [9]. Brain fog is also a common symptom in cases of chronic Lyme disease, parasitic infection, and autoimmune disease. 

Why Do You Get Brain Fog After COVID-19 Infection?

A 2022 literature review about COVID-19 and brain fog noted that as many as 1 in 3 COVID patients will develop cognitive deficits such as brain fog for weeks or months after infection. Based on this figure, the authors stated that cognitive impairment may be more common from the SARS-CoV-2 virus than from other viral diseases [10].

Autopsy, animal, and in vitro studies have shown the SARS-CoV-2 virus may lead to cognitive symptoms via the following mechanisms [4]: 

  • Infection of cells of the central nervous system 
  • Infection of neurons 
  • Increased neuroinflammation

Unfortunately, there’s something about the SARS-CoV-2 virus that can persist for long periods of time in tissues [1]. Additionally, it can infect the central nervous system, infect neurons, and cause neuroinflammation [4]. This inflammatory response can lead to blood-brain barrier dysfunction, oxidative stress, neuron degradation, and damage to small blood vessels that cause low oxygen levels and compromised brain function [1]. But don’t worry, these cognitive problems are all issues that can be fixed — we’re coming to that shortly.

Another reason brain fog is likely with long COVID is the sleep disturbance effect. 

A 2022 analysis of seven observational studies assessed the long-term neurological effects of COVID-19. A total of 3,304 long COVID patients who experienced symptoms long after their initial infection were included in the analysis. The results showed that the most common symptom was sleep disturbance, and this occurred in 63.1% of patients [3].

Loss of sleep significantly affects cognition, from learning ability to attention span, to memory. It’s no wonder that COVID long haulers are suffering from brain fog on a consistent lack of sleep. 

How Long Does Long COVID Brain Fog Last? 

It’s hard to say how long brain fog will last with long COVID, but current research suggests that brain fog and other symptoms like fatigue and sleep issues may persist for a period of weeks to months [11]. One study did look at patients who had persistent brain fog a full year after COVID-19 illness and found that having pre-existing depression was the strongest predictor of persistent brain fog following COVID-19 [12].

Risk Factors for Longer Lasting Brain Fog

Some factors that may increase the risk for long-lasting brain fog and other neurological symptoms following COVID-19 include the following:

  • Being female [13]
  • Having respiratory issues at the time of infection [13]
  • Admission to the ICU for COVID-19 [13, 14]
  • Having more severe COVID-19 illness [14]
  • Having depression prior to COVID-19 [12]
  • Multisystemic inflammatory syndrome in children [14]
  • Certain medications, including lopinavir-ritonavir and corticosteroids, during early stages COVID [14]

None of these are guarantees for having long-lasting brain fog post-COVID. But they are worth noting as far as creating a treatment plan that will address an individual’s root causes of brain fog.

How to Improve Long COVID Brain Fog

The good news for treating long COVID brain fog is that many of the fundamentals are similar to treating any other chronic health issue: you should have an anti-inflammatory, gut healing diet in place, you need to incorporate some kind of movement into your daily routine, and get into a healthy sleep pattern, especially if you are also experiencing sleep disruption. 

Beyond that, there are some additional supplements that can help speed recovery and restore mental clarity for COVID long haulers. Let’s dive in. 


Long COVID Brain Fog: What it is, Why it Happens, and How to Recover - What%20To%20Eat%20On%20The%20Paleo%20Diet 01 L

An healthy anti-inflammatory diet with plenty of antioxidants and a good ratio of protein, fat, and carbs. This ratio will look slightly different for everyone, but starting with your protein intake is a good idea. Getting 30-40 grams of protein at each meal is ideal to start, or more depending on your body weight and exercise regimen. 

For some people, a temporary low histamine diet may be beneficial to promote a less reactive immune system. 

Intermittent fasting may also be beneficial for some individuals to improve brain fog and cognitive function. But I have found that intermittent fasting is highly individual, and some people may find it difficult to sustain. If you are only eating 1-2 meals a day, you also still have to make sure you’re getting enough nutrition to meet your daily needs. 


Something that keeps coming up again and again lately in my conversations with other doctors like in my recent podcast with Dr. Hedberg is the importance of building and maintaining muscle mass for long-term health and using exercise as a core strategy to improve a number of chronic symptoms, including brain fog.

Another study involving patients with long COVID (55% had brain fog) found that 8 weeks of aerobic and resistance training significantly improved fatigue, functional status, quality of life, mood, and breathing difficulties [15]. 

Exercise is something you can and should start slow and build up over time to prevent burnout and injury. Try incorporating three workouts per week to start, one cardio and two resistance training. 


Many conditions can be improved by diet and lifestyle changes alone, but long COVID is likely to require some additional support, especially if you are still dealing with a lingering viral infection. Here are some supplements we recommend at the clinic for long COVID relief. 


I recommend probiotics for most people that come into our clinic because they have so many researched benefits and very few side effects. 

Probiotics may help to reduce the symptoms and severity of COVID-19. A randomized controlled trial involving 293 patients with symptomatic COVID-19 found that after 30 days, the probiotic group had [16]:

  • A higher rate of remission (53% vs. 28%)
  • A lower viral load in the nasal cavity and back of the throat
  • Fewer digestive and non-digestive symptoms
  • Higher IgG and IgM antibodies against SARS-COV2

While this study was conducted on acute COVID patients, it stands to reason that probiotic therapy would also have beneficial effects in long COVID treatment. From clinical experience, probiotics also tend to help other therapies work better by supporting the gut. 

Magnesium L-threonate

This is another interesting recommendation that came up in my conversation with Dr. Hedberg. Magnesium L-threonate is formulated to cross the blood-brain barrier and specifically increase magnesium levels in the brain [17]. Many people are already deficient in this essential mineral and it is only further depleted by stress and illness. Along with diet and lifestyle, this might be another good starting therapy to improve mental clarity, memory, and focus ability with long COVID. 

Omega 3 Fats

A 2022 literature review proposed that omega-3 fatty acids may be beneficial for COVID-related brain fog and brain health by reducing inflammation and oxidative stress, improving neuronal health, and by increasing glymphatic transport, which is the removal of toxins in the brain via cerebrospinal fluid, mostly occurring during sleep [18].


Similarly, melatonin is well known as a powerful antioxidant, sleep inducer, and promoter of glymphatic drainage in the brain. Similar to omega 3s, melatonin can improve brain detoxification and encourage immune system regulation post-COVID [19, 20, 21]. 

Quercetin and Luteolin

A 2021 literature review detailed how the natural flavonoid luteolin may be helpful for reducing long COVID-related brain fog. The review detailed how microglia (immune cells in the brain) and mast cells (immune cells that contribute to allergic responses) can become activated during COVID-19 in the brain and lead to neuroinflammation. 

The authors proposed that luteolin and quercetin could inhibit mast cells and neuroinflammation associated with COVID-19. They also cited evidence that luteolin and quercetin have anti-viral and anti-inflammatory properties, and can reduce cognitive decline [22].

How Many Supplements Do You Need?

I want to mention that normally, I take a less is more approach to supplementation. If you have the health foundations of diet, exercise, and sleep in place, you shouldn’t need too many additional inputs to keep you in a state of health. 

However, I recognize that patients with long COVID may need a bit more supplementation at first than other conditions might call for. In this case, a “top-down” approach is warranted, where we start out with a wider variety of treatments and narrow those down as symptoms improve. The results are worth sticking with it. 

You Can Recover a Healthy Brain Post COVID 

If you are dealing with long COVID brain fog right now, it may be difficult to see how you can get back to a healthy, capable brain. Don’t make the mistake of thinking you have to do it all by yourself! At the Ruscio Institute for Functional Medicine, we’ve helped hundreds of patients recover from brain fog and other chronic health conditions and return to a healthy, enjoyable life. Please click the link above to set up a free consultation with our staff and start your healing journey. 

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.

➕ References
  1. Premraj L, Kannapadi NV, Briggs J, Seal SM, Battaglini D, Fanning J, et al. Mid and long-term neurological and neuropsychiatric manifestations of post-COVID-19 syndrome: A meta-analysis. J Neurol Sci. 2022 Mar 15;434:120162. DOI: 10.1016/j.jns.2022.120162. PMID: 35121209. PMCID: PMC8798975.
  2. Lopez-Leon S, Wegman-Ostrosky T, Perelman C, Sepulveda R, Rebolledo PA, Cuapio A, et al. More than 50 long-term effects of COVID-19: a systematic review and meta-analysis. Sci Rep. 2021 Aug 9;11(1):16144. DOI: 10.1038/s41598-021-95565-8. PMID: 34373540. PMCID: PMC8352980.
  3. Patel UK, Mehta N, Patel A, Patel N, Ortiz JF, Khurana M, et al. Long-Term Neurological Sequelae Among Severe COVID-19 Patients: A Systematic Review and Meta-Analysis. Cureus. 2022 Sep 28;14(9):e29694. DOI: 10.7759/cureus.29694. PMID: 36321004. PMCID: PMC9616013.
  4. Proal AD, VanElzakker MB. Long COVID or Post-acute Sequelae of COVID-19 (PASC): An Overview of Biological Factors That May Contribute to Persistent Symptoms. Front Microbiol. 2021 Jun 23;12:698169. DOI: 10.3389/fmicb.2021.698169. PMID: 34248921. PMCID: PMC8260991.
  5. Au L, Capotescu C, Eyal G, Finestone G. Long covid and medical gaslighting: Dismissal, delayed diagnosis, and deferred treatment. SSM Qual Res Health. 2022 Dec;2:100167. DOI: 10.1016/j.ssmqr.2022.100167. PMID: 36092770. PMCID: PMC9448633.
  6. Jennings G, Monaghan A, Xue F, Duggan E, Romero-Ortuño R. Comprehensive clinical characterisation of brain fog in adults reporting long COVID symptoms. J Clin Med. 2022 Jun 15;11(12). DOI: 10.3390/jcm11123440. PMID: 35743516. PMCID: PMC9224578.
  7. Pinzon RT, Wijaya VO, Jody AA, Nunsio PN, Buana RB. Persistent neurological manifestations in long COVID-19 syndrome: A systematic review and meta-analysis. J Infect Public Health. 2022 Aug;15(8):856–69. DOI: 10.1016/j.jiph.2022.06.013. PMID: 35785594. PMCID: PMC9221935.
  8. Ocon AJ. Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome. Front Physiol. 2013 Apr 5;4:63. DOI: 10.3389/fphys.2013.00063. PMID: 23576989. PMCID: PMC3617392.
  9. Proal A, Marshall T. Myalgic encephalomyelitis/chronic fatigue syndrome in the era of the human microbiome: persistent pathogens drive chronic symptoms by interfering with host metabolism, gene expression, and immunity. Front Pediatr. 2018 Dec 4;6:373. DOI: 10.3389/fped.2018.00373. PMID: 30564562. PMCID: PMC6288442.
  10. Nouraeinejad A. Brain fog as a Long-term Sequela of COVID-19. SN Compr Clin Med. 2023;5(1):9. DOI: 10.1007/s42399-022-01352-5. PMID: 36466122. PMCID: PMC9685075.
  11. Lopez-Leon S, Wegman-Ostrosky T, Ayuzo Del Valle NC, Perelman C, Sepulveda R, Rebolledo PA, et al. Long-COVID in children and adolescents: a systematic review and meta-analyses. Sci Rep. 2022 Jun 23;12(1):9950. DOI: 10.1038/s41598-022-13495-5. PMID: 35739136. PMCID: PMC9226045.
  12. Cristillo V, Pilotto A, Piccinelli SC, Gipponi S, Leonardi M, Bezzi M, et al. Predictors of “brain fog” 1 year after COVID-19 disease. Neurol Sci. 2022 Oct;43(10):5795–7. DOI: 10.1007/s10072-022-06285-4. PMID: 35930181. PMCID: PMC9361921.
  13. Asadi-Pooya AA, Akbari A, Emami A, Lotfi M, Rostamihosseinkhani M, Nemati H, et al. Long COVID syndrome-associated brain fog. J Med Virol. 2022 Mar;94(3):979–84. DOI: 10.1002/jmv.27404. PMID: 34672377. PMCID: PMC8662118.
  14. Joshee S, Vatti N, Chang C. Long-Term Effects of COVID-19. Mayo Clin Proc. 2022 Mar;97(3):579–99. DOI: 10.1016/j.mayocp.2021.12.017. PMID: 35246288. PMCID: PMC8752286.
  15. Jimeno-Almazán A, Franco-López F, Buendía-Romero Á, Martínez-Cava A, Sánchez-Agar JA, Sánchez-Alcaraz Martínez BJ, et al. Rehabilitation for post-COVID-19 condition through a supervised exercise intervention: A randomized controlled trial. Scand J Med Sci Sports. 2022 Dec;32(12):1791–801. DOI: 10.1111/sms.14240. PMID: 36111386. PMCID: PMC9538729.
  16. Gutiérrez-Castrellón P, Gandara-Martí T, Abreu Y Abreu AT, Nieto-Rufino CD, López-Orduña E, Jiménez-Escobar I, et al. Probiotic improves symptomatic and viral clearance in Covid19 outpatients: a randomized, quadruple-blinded, placebo-controlled trial. Gut Microbes. 2022 Dec;14(1):2018899. DOI: 10.1080/19490976.2021.2018899. PMID: 35014600. PMCID: PMC8757475.
  17. Zhang C, Hu Q, Li S, Dai F, Qian W, Hewlings S, et al. A Magtein®, Magnesium L-Threonate, -Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults. Nutrients. 2022 Dec 8;14(24). DOI: 10.3390/nu14245235. PMID: 36558392. PMCID: PMC9786204.
  18. Yang C-P, Chang C-M, Yang C-C, Pariante CM, Su K-P. Long COVID and long chain fatty acids (LCFAs): Psychoneuroimmunity implication of omega-3 LCFAs in delayed consequences of COVID-19. Brain Behav Immun. 2022 Jul;103:19–27. DOI: 10.1016/j.bbi.2022.04.001. PMID: 35390469. PMCID: PMC8977215.
  19. Tordjman S, Chokron S, Delorme R, Charrier A, Bellissant E, Jaafari N, et al. Melatonin: pharmacology, functions and therapeutic benefits. Curr Neuropharmacol. 2017 Apr;15(3):434–43. DOI: 10.2174/1570159X14666161228122115. PMID: 28503116. PMCID: PMC5405617.
  20. Zisapel N. New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. Br J Pharmacol. 2018 Aug;175(16):3190–9. DOI: 10.1111/bph.14116. PMID: 29318587. PMCID: PMC6057895.
  21. Cardinali DP, Brown GM, Pandi-Perumal SR. Possible application of melatonin in long COVID. Biomolecules. 2022 Nov 7;12(11). DOI: 10.3390/biom12111646. PMID: 36358996. PMCID: PMC9687267.
  22. Theoharides TC, Cholevas C, Polyzoidis K, Politis A. Long-COVID syndrome-associated brain fog and chemofog: Luteolin to the rescue. Biofactors. 2021 Mar;47(2):232–41. DOI: 10.1002/biof.1726. PMID: 33847020. PMCID: PMC8250989.

Need help or would like to learn more?
View Dr. Ruscio’s, DC additional resources

Get Help


I care about answering your questions and sharing my knowledge with you. Leave a comment or connect with me on social media asking any health question you may have and I just might incorporate it into our next listener questions podcast episode just for you!