The Top 12 Supplements for Brain Fog and Concentration

There is strong evidence that Rhodiola Rosea improves cognition, with Examine.com rating the evidence as grade A. Rhodiola Rosea as a supplement is a herb derived from plant root, commonly taken as capsule (standardised extract). Studies typically use 200–600mg.

Rhodiola rosea is a root herb that grows in cold, mountainous regions of Europe and Asia. It is known to help the body cope with physical and mental stress, reducing fatigue and improving mood and attention. It can also support exercise performance by reducing perceived effort and the muscle damage associated with intense training. Effects on mental clarity and stress tend to be noticed within a few days to a couple of weeks. It is usually taken as a standardised extract capsule in the morning.

There is strong evidence that Caffeine improves attention, with Examine.com rating the evidence as grade A. Caffeine as a supplement is a stimulant derived from naturally occurring (coffee / tea), commonly taken as capsule or powder or drink. Studies typically use 3–6mg per kg bodyweight.

Caffeine is a naturally occurring stimulant found in coffee, tea, and cacao. It is one of the most researched performance-enhancing compounds available, known to improve endurance, strength, power output, and reaction time during exercise. It also improves alertness and reduces perceived effort, making hard training feel more manageable. It is available as a capsule or powder, though most people obtain it from coffee or pre-workout drinks. Effects are dose-dependent and tolerance builds with regular use, so cycling off periodically helps to maintain its effectiveness.

There is good evidence that L-Tyrosine improves attention, with Examine.com rating the evidence as grade B. L-Tyrosine as a supplement is a amino acid derived from synthetic / food-derived, commonly taken as capsule or powder. Studies typically use 500–2000mg.

L-tyrosine is an amino acid the body uses to produce several important signalling chemicals, including those involved in mood, focus, and the stress response. It can support mental clarity and alertness during demanding situations. It is available as a capsule or powder and is commonly taken before periods of stress or intense mental effort.

There is good evidence that Theanine improves attention, with Examine.com rating the evidence as grade B. Theanine as a supplement is a amino acid derived from tea plant, commonly taken as capsule or powder. Studies typically use 100–200mg.

L-theanine is an amino acid found naturally in green tea leaves. It promotes alpha brain wave activity, which is associated with a calm, focused mental state, without causing drowsiness. It is one of the gentlest options available and is well tolerated by most people. It comes as a capsule or powder and can be taken during the day or before bed.

There is good evidence that Folic Acid (Vitamin B9) improves cognition, with Examine.com rating the evidence as grade B. Folic Acid (Vitamin B9) as a supplement is a vitamin derived from synthetic, commonly taken as tablet or capsule. Studies typically use 400–800mcg.

Folic acid is the synthetic form of folate, a B vitamin essential for cell production and repair. It is particularly important during pregnancy and can support mood and cognitive function in adults. It is widely available as a tablet or capsule, often as part of a B-complex supplement.

There is good evidence that Ginkgo Biloba improves cognition, with Examine.com rating the evidence as grade B. Ginkgo Biloba as a supplement is a herb derived from ginkgo tree leaf, commonly taken as capsule or tablet. Studies typically use 120–240mg.

Ginkgo biloba is extracted from the leaves of one of the oldest tree species on earth and has been used in traditional medicine for centuries. It is known to improve circulation, including blood flow to the brain, and research shows it can support memory, concentration, and mental clarity. It is one of the most studied herbal supplements available. It is taken as a capsule or tablet, usually once or twice a day.

There is good evidence that Panax Ginseng (Korean Ginseng) improves attention, with Examine.com rating the evidence as grade B. Panax Ginseng (Korean Ginseng) as a supplement is a herbal adaptogen derived from plant root, commonly taken as capsule or extract. Studies typically use 200–400mg.

Panax ginseng is a root that has been used in traditional medicine for centuries, particularly in East Asia. It is known to support mental alertness and physical stamina, and can help the body manage the effects of stress and fatigue. It is typically taken as a capsule or standardised extract.

There is good evidence that Phosphatidylserine improves attention, with Examine.com rating the evidence as grade B. Phosphatidylserine as a supplement is a phospholipid derived from soy or sunflower-derived, commonly taken as softgel or capsule. Studies typically use 100–400mg.

Phosphatidylserine is a fatty substance found in high concentrations in brain cells, where it plays an important role in keeping them functioning well. It is known to support memory, attention, and the ability to manage stress. It is typically taken as a softgel or capsule.

There is good evidence that Probiotics improves cognition, with Examine.com rating the evidence as grade B. Probiotics as a supplement is a live cultures derived from fermented bacteria, commonly taken as capsule or powder. Studies typically use 1–50 billion CFU.

Probiotics are live bacteria that, when taken in sufficient quantities, support the health of the gut. They are known to relieve digestive symptoms including bloating, abdominal pain, constipation, and diarrhoea. They can also have a positive effect on mood, sleep quality, and skin conditions such as eczema. Different strains target different conditions, so the specific product matters. They are available as capsules or powders and should be refrigerated or stored as directed to keep the cultures active.

There is good evidence that Curcumin improves cognition, with Examine.com rating the evidence as grade B. Curcumin as a supplement is a polyphenol derived from turmeric root, commonly taken as capsule. Studies typically use 500–1500mg.

Curcumin is the active compound in turmeric, a spice widely used in South Asian cooking. It is known to reduce inflammation in the body and can support joint comfort and recovery. It is also known to have a positive effect on mood and may support memory and focus. Because it is poorly absorbed on its own, it is best taken with black pepper extract (piperine) or in a formulation designed to improve bioavailability. It is most commonly available as a capsule.

There is good evidence that N-Acetylcysteine improves working memory, with Examine.com rating the evidence as grade B. N-Acetylcysteine as a supplement is a amino acid derivative derived from naturally occurring (also synthesised), commonly taken as capsule or effervescent tablet. Studies typically use 600–1800mg.

N-Acetylcysteine, or NAC, is a compound derived from the amino acid cysteine and is a precursor to glutathione — one of the body's most important antioxidants. It is known to support liver health and is used clinically to treat paracetamol overdose. It can also help to reduce obsessive and compulsive symptoms, ease respiratory conditions by thinning mucus, and support mental health in conditions involving oxidative stress. It is available as a capsule or effervescent tablet and is generally well tolerated.

There is good evidence that Medium-chain Triglycerides improves cognition, with Examine.com rating the evidence as grade B. Medium-chain Triglycerides as a supplement is a fatty acid derived from coconut / palm kernel oil, commonly taken as oil or powder or capsule. Studies typically use 5–15g.

Medium-chain triglycerides, or MCTs, are a type of fat found in coconut oil and palm kernel oil that is absorbed and metabolised more quickly than most dietary fats. They are converted rapidly into energy by the liver and can be used as a fuel source during exercise. They are known to support fat metabolism and can help to reduce appetite and support weight management. MCT oil is a popular addition to coffee and smoothies, and is also available as a capsule or powder.