What are the best supplements for brain fog? 10 Expert Picks for Mental Clarity
- re:health
- Sep 24
- 14 min read
Key Takeaways:
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Table of Contents
Do You Have Brain Fog? Recognising the Symptoms
Brain fog isn't a medical diagnosis – it's a collection of symptoms that leave you feeling like you're thinking through cotton wool. If you've ever struggled to find the right word mid-conversation, forgotten why you walked into a room, or felt mentally exhausted after simple tasks, you've likely experienced brain fog.
Common brain fog symptoms include:
Difficulty concentrating or staying focused
Memory problems, especially short-term memory
Mental fatigue that doesn't improve with rest
Trouble finding words or completing thoughts
Feeling "cloudy" or "fuzzy" mentally
Difficulty making decisions
Reduced mental stamina
Feeling disconnected or "not quite there"
These symptoms can range from occasional mild episodes to persistent, life-disrupting cognitive cloudiness that affects work, relationships, and daily functioning.
What Causes Brain Fog in 2025?
Understanding what's driving your brain fog is crucial because supplements only help when they target the underlying cause. Brain fog typically stems from three main categories:
Lifestyle Factors
Chronic stress overwhelming your nervous system
Poor sleep quality or insufficient sleep
Blood sugar imbalances from processed foods and irregular eating
Dehydration affecting brain function
Sedentary lifestyle reducing circulation and neuroplasticity
Medical Conditions
Thyroid disorders (both overactive and underactive)
Hormonal changes during perimenopause, menopause, or postpartum
Long COVID and post-viral fatigue syndromes
Autoimmune conditions causing inflammation
Mould exposure and environmental toxins
Chronic infections like Lyme disease or Epstein-Barr virus
Nutrient Deficiencies
B vitamin deficiencies affecting energy and neurotransmitter production
Omega-3 insufficiency impacting brain cell membranes
Mineral deficiencies particularly magnesium, zinc, and iron
Vitamin D deficiency affecting mood and cognitive function
For a deeper dive into identifying your specific root causes, explore our comprehensive Functional Medicine Guide to Brain Fog.
Remember: Supplements only help when we understand what's driving your symptoms.
Can Supplements Help Brain Fog?
You've probably seen headlines claiming "brain supplements don't live up to the hype" - and they're not wrong. The supplement industry is flooded with products making bold claims without solid evidence.
However, this doesn't mean all supplements for brain fog are useless. The key difference lies in targeting specific nutrient deficiencies and supporting known biological pathways that affect cognitive function.
Here, we focus exclusively on nutrients with strong evidence from peer-reviewed research and clinical experience. These aren't magic bullets – they're targeted tools that work best when:
You understand your underlying causes
They're combined with proper nutrition and lifestyle changes
You're working with appropriate dosages and forms
You give them adequate time to work (typically 6-12 weeks)
Our selection criteria for these 10 supplements:
Robust scientific evidence from human studies
Clear mechanisms of action for cognitive symptoms
Good safety profiles when used appropriately
Clinical relevance in functional medicine practice
Bioavailable forms that the body can actually use
The 10 Best Supplements for Brain Fog
1. Omega-3 Fatty Acids (Fish Oil or Algal Oil)
What it is: Essential fatty acids, particularly EPA and DHA, that form the structural foundation of brain cell membranes.
Why it helps: Your brain is nearly 60% fat, and omega-3s keep cell membranes fluid and functional. They also reduce neuroinflammation – a key driver of brain fog – and support neurotransmitter production.
The evidence: A 2022 systematic review analyzing 9 randomized controlled trials with over 1,300 participants found that omega-3 supplementation significantly improves learning, memory, cognitive well-being, and blood flow in the brain. For attention-related symptoms specifically, a 2019 study in Translational Psychiatry demonstrated that high-dose EPA (1,200mg daily) improved focused attention and vigilance in those with low baseline EPA levels. Additionally, a large 2023 meta-analysis of over 100,000 participants found that omega-3 intake reduced risk of cognitive decline by approximately 20%.
Best for: People with inflammatory conditions, those eating little fish, anyone with attention difficulties or mood-related brain fog.
What to look for: High EPA content (aim for EPA:DHA ratio of 2:1 or 3:1), third-party tested for purity, from sustainable sources.
2. B-Complex Vitamins (Especially B6, B9, B12)
What it is: A group of water-soluble vitamins essential for energy metabolism, neurotransmitter synthesis, and methylation processes.
Why it helps: B vitamins are needed for producing dopamine, serotonin, and norepinephrine – neurotransmitters crucial for focus and mental clarity. They also support methylation, a process that affects gene expression and brain detoxification.
Why it helps: B vitamins are cofactors in producing dopamine, serotonin, and norepinephrine – neurotransmitters crucial for focus and mental clarity. A comprehensive 2016 review explains that vitamin B6 is vital for making key neurotransmitters including dopamine, serotonin, and GABA. Meanwhile, B12 and folate support DNA synthesis and methylation processes that are essential for brain function.
The evidence: B12 deficiency is directly linked to cognitive impairment, with supplementation shown to slow brain atrophy in those with mild cognitive decline. Folate deficiency correlates with depression and mental fatigue, while B6 deficiency impairs neurotransmitter production, affecting mood and cognition.
Best for: Vegetarians, vegans, people over 50, those with digestive issues affecting absorption, anyone taking acid-reducing medications.
What to look for: Methylated forms (methylcobalamin, methylfolate, P5P) for better absorption, especially if you have genetic variations affecting methylation.
3. Vitamin D
What it is: A hormone-like vitamin that regulates over 1,000 genes, including many involved in brain function and mood regulation.
Why it helps: Vitamin D receptors are found throughout the brain, particularly in areas associated with mood and cognition. The vitamin maintains brain health by regulating neural development, balancing neurotransmitters like dopamine and serotonin, and reducing neuroinflammation.
The evidence: A 2013 meta-analysis of over 31,000 people found that low vitamin D levels significantly increased the risk of depression. Additionally, research shows vitamin D levels are significantly lower in people with cognitive impairment and dementia, with deficiency linked to executive dysfunction, impaired processing speed, and memory problems.
Best for: Most people living in northern climates, those with limited sun exposure, people with autoimmune conditions, anyone experiencing seasonal mood changes.
What to look for: Vitamin D3 (cholecalciferol) rather than D2, ideally combined with vitamin K2 for optimal absorption.
4. Magnesium
What it is: An essential mineral involved in over 300 enzymatic reactions, including those crucial for nervous system function and energy production.
Why it helps: Magnesium acts as nature's "chill pill," regulating the stress response and supporting quality sleep. It's also required for ATP (cellular energy) production and neurotransmitter balance. The mineral plays an inhibitory role in stress response regulation and maintains nerve signal transmission.
The evidence: Research demonstrates that magnesium deficiency and stress create a vicious circle - stress depletes magnesium while deficiency increases stress susceptibility. Studies show magnesium supplementation reduces cortisol levels and improves stress resilience. Additionally, a 2022 study found that magnesium L-threonate significantly improved all cognitive function categories, while 2024 research confirmed improvements in sleep quality, mood, and mental performance.
Best for: Highly stressed individuals, poor sleepers, people with muscle tension or headaches, those eating processed foods.
What to look for: Highly absorbable forms like magnesium glycinate or magnesium L-threonate. Avoid magnesium oxide, which is poorly absorbed.
5. Zinc
What it is: An essential trace mineral crucial for neurotransmitter function, immune system regulation, and brain plasticity.
Why it helps: Zinc is required for dopamine production and helps regulate the stress hormone cortisol. It's also essential for neuroplasticity – your brain's ability to form new connections. Zinc is required in the synthesis of several neurotransmitters, including dopamine, serotonin, and norepinephrine, and enhances GABA, one of our main calming neurotransmitters.
The evidence: Clinical trials show zinc supplementation significantly reduces symptoms of hyperactivity, impulsivity, and attention problems in people with ADHD. Research consistently demonstrates that zinc deficiency is closely related to cognitive impairment and memory problems, while adequate levels support learning and neuroplasticity. Studies also show zinc helps manage stress response by regulating cortisol production.
Best for: People with digestive issues, vegetarians, those with high stress levels, anyone with recurring infections or slow wound healing.
What to look for: Chelated forms like zinc bisglycinate for better absorption. Always take with food to avoid stomach upset.
Special note: Zinc deficiency can be related to a condition called pyrrole disorder, which affects many people with mood and cognitive issues. Learn more in our guide to Identifying Pyrroles and Mental Health.
6. Lion's Mane Mushroom
What it is: A medicinal mushroom containing unique compounds called hericenones and erinacines that support nerve growth and brain plasticity.
Why it helps: Lion's Mane stimulates production of nerve growth factor (NGF), promoting the growth and repair of brain cells. Laboratory studies show the mushroom extract promotes neuron projections, extending and connecting to other neurons, with compounds largely increasing the size of growth cones essential for brain cell connections.
The evidence: Multiple studies show Lion's Mane improves cognitive function in middle-aged and older adults, with a 16-week trial in people with mild cognitive impairment showing improved performance on cognitive tests. However, recent research in healthy young adults shows mixed results, suggesting benefits may be more pronounced in older adults or those with existing cognitive decline.
Best for: People experiencing age-related cognitive decline, those recovering from brain injuries, anyone wanting to enhance neuroplasticity and learning.
What to look for: Standardised extracts containing both mycelium and fruiting body, with guaranteed levels of active compounds.
7. Rhodiola Rosea
What it is: An adaptogenic herb that helps the body manage stress and maintain balance during challenging periods.
Why it helps: Rhodiola modulates the stress response system, reducing cortisol levels and supporting neurotransmitter balance. It stimulates the brain and increases concentration levels of neurotransmitters such as norepinephrine, serotonin, and dopamine, particularly effective for stress-induced mental fatigue.
The evidence: A comprehensive 2022 review found that clinical trials support Rhodiola's effectiveness in managing stress-induced conditions, cognitive functions, and mental performance. A 12-week study showed significant improvements in attention network tasks, reaction times, and mental resource allocation, while another trial found significant reductions in anxiety, stress, depression, and improvements in total mood after 14 days.
Best for: Highly stressed individuals, people with demanding jobs, those experiencing burnout or chronic fatigue.
What to look for: Standardised extracts containing 3% rosavins and 1% salidroside, the active compounds responsible for adaptogenic effects.
8. Creatine
What it is: A compound that supplies rapid energy to cells, particularly during high-demand activities. While known for muscle performance, it's equally important for brain energy.
Why it helps: Your brain consumes about 20% of your body's energy, and creatine helps maintain ATP (cellular energy) levels during mental tasks. In the brain, creatine may improve cognitive performance by increasing cellular energy reserves and reducing oxidative stress, particularly important in tasks requiring high cognitive processing.
The evidence: A 2024 systematic review and meta-analysis of 16 studies with 492 participants found that creatine supplementation showed significant positive effects on memory, attention time, and processing speed. Research consistently shows creatine improves cognitive performance particularly under stress conditions like sleep deprivation, mental fatigue, and hypoxia. Studies demonstrate creatine is particularly beneficial for vegetarians who typically have lower creatine levels.
Best for: Vegetarians and vegans, people with high mental demands, those experiencing stress-related cognitive decline, anyone with chronic fatigue.
What to look for: Creatine monohydrate is the most researched form. Take consistently for several weeks to build up muscle and brain stores.
9. CoQ10 (Coenzyme Q10)
What it is: A naturally occurring compound found in every cell that plays a crucial role in cellular energy production within mitochondria. Also functions as a powerful antioxidant protecting cells from oxidative damage.
Why it helps: CoQ10 levels in the brain are significantly associated with cognitive functioning and executive function in older adults, with lower levels linked to cognitive decline and reduced antioxidant defenses. The brain consumes about 20% of the body's energy, and CoQ10 helps maintain ATP (cellular energy) levels during mental tasks while reducing oxidative stress in brain tissue. It supports mitochondrial function, reduces neuroinflammation, and may protect against neuronal damage.
The evidence: Clinical studies suggest CoQ10 supplementation around 100-400mg per day appears to boost cognitive performance in older adults, with a meta-analysis finding "moderate evidence" that CoQ10 improves general cognition, especially executive function. A 12-week randomized controlled trial using 200mg per day of ubiquinol found significantly improved clarity of thought and concentration in older adults. However, larger clinical trials in Alzheimer's disease have shown mixed results, and evidence for preventing dementia remains limited.
Best for: People over 40 (when natural CoQ10 production declines), those with high mental demands, individuals experiencing brain fog or mental fatigue, people taking statin medications (which deplete CoQ10).
What to look for: Ubiquinol (the active form) may be superior to ubiquinone for absorption, especially in people over 50. A 2018 study found ubiquinol led to 1.5-fold higher blood levels compared to ubiquinone. Take with fatty meals for better absorption, typical doses range from 100-300mg daily.
Long COVID connection: Many Long COVID patients experience significant improvement in brain fog and fatigue with CoQ10 supplementation.
Read more in our comprehensive guide to Refuelling the Long COVID Brain.
10. Phosphatidylserine
What it is: An essential phospholipid that forms a critical component of cell membranes, particularly abundant in brain tissue where it facilitates communication between neurons and supports membrane integrity.
Why it helps: PS is required for healthy nerve cell membranes and myelin, supporting the formation of short-term memory, consolidation of long-term memory, ability to focus attention and concentrate, and neurotransmission. PS crosses the blood-brain barrier to support brain function and fights brain fog while inhibiting inflammation to support brain and nervous system health. PS modulates neuroinflammation, neurotransmission, and synaptic refinement while supporting acetylcholine release.
The evidence: A 2024 randomized controlled trial in 190 adults with mild cognitive impairment found that PS supplementation significantly improved short-term memory, arithmetic testing, and similarity tests over 12 months. A landmark study of 149 patients with age-associated memory impairment found that those treated with 300mg daily PS for 12 weeks improved on learning and memory tasks compared to placebo. In children with ADHD, PS supplementation significantly improved symptoms and short-term auditory memory.
Best for: Adults over 50 experiencing memory concerns, people with high stress and cognitive demands, individuals with brain fog or attention difficulties, those seeking to maintain cognitive sharpness with aging.
What to look for: Soy-derived phosphatidylserine is the safest option (avoiding past concerns with bovine-derived forms). Effective doses range from 300-800mg daily, typically divided into 100mg doses taken 3 times daily. Taking PS in the morning may help improve cognitive function, attention and focus throughout the day.
What Else Can Help Brain Fog?
Supplements work best as part of a comprehensive approach. Here are other evidence-based strategies for clearing mental fog:
Nutrition Fundamentals
Stabilise blood sugar through balanced meals with protein, healthy fats, and complex carbohydrates
Anti-inflammatory diet including fatty fish, leafy greens, berries, and turmeric
Adequate hydration – even mild dehydration affects cognitive function
Limiting processed foods and refined sugars that create blood sugar swings
For specific dietary approaches, explore our guide on Brain Fog and Keto.
Lifestyle Optimisation
Quality sleep of 7-9 hours with consistent sleep-wake times
Regular exercise to improve circulation and neuroplasticity
Stress management through meditation, yoga, or other relaxation practices
Morning sunlight exposure to regulate circadian rhythms
Digital detox periods to reduce cognitive overload
Environmental Factors
Addressing mould exposure in home or workplace environments
Reducing toxic load from chemicals, plastics, and pollution
Optimising indoor air quality with proper ventilation and air filtration
Managing electromagnetic fields (EMFs) from devices and WiFi
The Gut-Brain Connection
Your gut health directly impacts brain function through the vagus nerve and immune system. Supporting digestive health often improves mental clarity significantly.
Learn more about this crucial connection in our detailed guide to The Gut-Brain Connection.
Test Don't Guess – Work With a Professional
While these supplements can be incredibly helpful, the most effective approach to brain fog is identifying and addressing specific underlying drivers through comprehensive testing.
Advanced functional testing can reveal:
Nutrient deficiencies through comprehensive blood panels and micronutrient analysis
Hormonal imbalances via DUTCH testing (dried urine comprehensive hormones)
Genetic variations affecting methylation, detoxification, and neurotransmitter metabolism
Toxic burden including heavy metals, moulds, and environmental toxins
Immune dysfunction and chronic infections
Gut health status through comprehensive stool analysis
Mitochondrial function via organic acid testing (OAT)
Specialised Brain Health Assessment
At Re:Health Clinic, we offer a comprehensive Brain MOT that includes advanced testing, detailed analysis, and personalised protocols combining targeted supplementation with nutrition and lifestyle interventions.
Ready to uncover your underlying risk factors?
If brain fog is interfering with your daily life, work, or relationships, don't continue struggling alone. Our functional medicine approach has helped hundreds of clients regain mental clarity and cognitive energy.
Frequently Asked Questions
What vitamin deficiency causes brain fog?
The most common vitamin deficiencies linked to brain fog are B12, folate (B9), vitamin D, and B6. B12 deficiency is particularly notorious for causing cognitive symptoms, memory problems, and mental fatigue. However, brain fog is rarely caused by a single nutrient deficiency – it's usually multifactorial.
How long does it take supplements to work for brain fog?
Most people begin noticing improvements within 2-4 weeks of consistent supplementation, with more significant changes occurring at 6-12 weeks. However, this depends on your individual deficiency levels, absorption capacity, and underlying causes. Some supplements like creatine may take 4-6 weeks to build up effective levels.
Are there natural solutions to brain fog?
Yes, brain fog can often be significantly improved or resolved through natural approaches, including targeted supplementation, nutrition optimisation, lifestyle changes, and addressing root causes. However, persistent brain fog should be evaluated by a healthcare professional to rule out underlying medical conditions.
Is it safe to take all these supplements together?
While these supplements are generally safe, it's important to consider interactions, individual needs, and appropriate dosages. Some nutrients compete for absorption (like zinc and iron), while others work synergistically. Working with a qualified practitioner ensures you get the right combination for your specific situation.
Is it safe to take supplements if I am on medication?
Some medications and supplements have severe interactions. If you are on any medications we would always recommend working with an expert or speaking to your healthcare provider to ensure they are suitable for you.
What's the difference between brain fog supplements and nootropics?
Brain fog supplements typically address nutritional deficiencies and support basic brain function, while nootropics are substances specifically designed to enhance cognitive performance beyond normal levels. The supplements in this article focus on restoring optimal brain function rather than enhancement.
Can stress cause brain fog?
Absolutely. Chronic stress elevates cortisol levels, which can impair memory formation, reduce neuroplasticity, and create inflammation in the brain. Stress also disrupts sleep and digestion, further contributing to cognitive symptoms. Adaptogens like Rhodiola and stress-supporting nutrients like magnesium and B vitamins can be particularly helpful.
Can I take supplements if I am pregnant or breastfeeding?
Always consult with your healthcare provider before starting any new supplements during pregnancy or while breastfeeding.
Can supplements help with perimenopause related brain fog?
Perimenopause brain fog is incredibly common, affecting up to 60% of women during this transition. The hormonal fluctuations, particularly declining estrogen levels, directly impact neurotransmitter production, blood flow to the brain, and mitochondrial function in brain cells. The key is addressing both the hormonal component and the downstream effects on brain function. Many women find that a targeted supplement approach, combined with lifestyle modifications like prioritising sleep and stress management, can significantly improve mental clarity during this challenging transition.
What supplements can help with Long COVID brain fog?
Long COVID brain fog appears to involve multiple mechanisms including persistent neuroinflammation, mitochondrial dysfunction, blood-brain barrier disruption, and autoimmune processes affecting the brain. This makes it particularly complex to address. Research and clinical experience suggest the above supplements may be helpful. The timeline for improvement can be longer with Long COVID brain fog - many people need 3-6 months of consistent supplementation to see significant changes. It's also crucial to work with healthcare providers familiar with Long COVID, as the condition often requires a multi-faceted approach.
About the Author
Ruth Etches, Nutritional Therapist & Functional Medicine Practitioner
Ruth is a leading practitioner in brain and mental health, with advanced training in Integrative and Nutritional Psychiatry. She is also a certified Bredesen practitioner, offering the ReCode and PreCode protocols for Alzheimer's prevention and cognitive optimisation.
With many years of clinical experience, Ruth specialises in uncovering the triggers and drivers of complex conditions such as anxiety, depression, ADHD, bipolar disorder, OCD, schizophrenia, cognitive decline, and mould-related illness. She uses advanced functional testing - including genetics, organic acids, hormone panels, immune markers, and gut analysis - to create highly personalised nutrition and lifestyle strategies.
Ruth is the founder of Re:Health Clinic, where she and her team provide compassionate, evidence-based support to clients across the UK and internationally. Her approach blends cutting-edge science with a deeply personalised, holistic philosophy: no stone unturned.
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