OTC Supplements

Lithium orotate is a lithium salt sold over the counter as a low-dose supplement, far below the doses of prescription lithium carbonate. Interest rose after a 2025 Nature study that restored brain lithium with lithium orotate in mice and prevented Alzheimer-like changes. There are no controlled human trials of lithium orotate itself. Whether the orotate salt behaves differently from other lithium salts is disputed.

Magnesium is an essential mineral sold in many salt forms. Meta-analyses of randomised trials find modest drops in blood pressure, largest in people with hypertension or low magnesium. They also find improved insulin resistance with longer use and fewer migraine attacks. Evidence for sleep and depression is weaker but positive. Which salt matters less than marketing suggests.

Creatine is one of the most researched sports supplements. It is best known for building strength and muscle, and is increasingly studied for the brain. Meta-analyses of randomised trials find small-to-moderate improvements in memory, attention and processing speed. The effects on memory are largest in older adults. It is well tolerated at 3 to 5 g a day.

L-theanine is an amino acid found almost only in tea. Taken at 200 to 400 mg a day, it may reduce stress and anxiety in people under stressful conditions. Its best-known use is alongside caffeine, where the pair improves attention switching more than either alone. A 2025 meta-analysis found small improvements in subjective sleep.

Alpha-lipoic acid (ALA) is a sulfur-containing mitochondrial cofactor, used as a racemic drug for the pain and pins-and-needles of diabetic nerve damage. Meta-analyses of randomised trials support it for diabetic neuropathy symptoms. Its effects on weight and blood sugar are real but small. Supplements come as the racemic mix, as pure R-ALA, or as Na-R-ALA, a sodium salt of R-ALA made to absorb better.

Coenzyme Q10 (CoQ10) is part of the mitochondrial energy chain and one of the most widely used supplements. Its best evidence is in chronic heart failure. There, the Q-SYMBIO trial found fewer major cardiovascular events and deaths over two years. For statin muscle pain, migraine and blood pressure, the results are mixed or modest.

PQQ (pyrroloquinoline quinone) is a redox cofactor first found in bacteria. Mammals do not make it but take in trace amounts from food. In cells it switches on mitochondrial biogenesis through the PGC-1α pathway. In humans, small 12-week trials of PQQ disodium salt reported better memory and attention scores.

Ubiquinol is the reduced, electron-carrying form of coenzyme-q10, sold as a better-absorbed version. One small study found it raised blood CoQ10 more than ubiquinone. A randomised crossover study in older adults found no significant difference. Its most notable trial is in multiple-system atrophy, where high doses improved a motor score.

Alpha-GPC (choline alfoscerate) is a choline-containing phospholipid breakdown product, sold as a prescription drug in some countries and a supplement elsewhere. It is a precursor of both choline and acetylcholine. Its record is unusually mixed. One very large Korean cohort linked it to lower dementia conversion, while another linked it to higher 10-year stroke risk.

Caffeine is the world's most widely used psychoactive compound, a methylxanthine that works by blocking adenosine receptors. At low to moderate doses it reliably improves alertness, vigilance, attention and reaction time, with weaker and less consistent effects on memory and higher-order judgement. It is the reference point every other stimulant on this wiki gets compared to.

Citicoline (CDP-choline) is an intermediate in the synthesis of phosphatidylcholine, the main phospholipid in cell membranes. It is a prescription drug in some countries and a supplement in others. A meta-analysis found it improved cognitive status in mild cognitive impairment, Alzheimer's disease and post-stroke dementia, though the underlying studies were of poor quality.

Melatonin is the hormone the pineal gland releases at night to signal darkness. Taken as a supplement, its most convincing use is jet lag, where a Cochrane review put the number needed to treat at 2. For insomnia the benefit is real but modest: about 7 minutes faster sleep onset and 8 minutes more sleep on average. Timing matters as much as dose.

Phosphatidylserine (PS) is a membrane phospholipid sold for memory. The strongest early trial used PS extracted from cow brain, in 494 elderly patients with cognitive decline. Soy-derived PS, developed as an alternative to bovine PS, has smaller trials showing memory gains in older adults with memory complaints. Smaller studies suggest it blunts the cortisol response to stress.

Bacopa monnieri is an Ayurvedic herb used traditionally to support memory. Randomised trials in healthy older adults found better verbal learning and delayed recall after about 12 weeks. A meta-analysis of nine trials found faster attention (Trail B) and choice reaction time. It is slow to act and commonly causes gut side effects.

Citrus bergamot is a flavonoid-rich extract of the bergamot orange, sold to lower cholesterol. Several small randomised trials found lower LDL cholesterol. A 2026 meta-analysis of nine trials found modest improvements in blood pressure, glucose and insulin resistance, and rated trial results as inconsistent. A network meta-analysis ranked it among the most effective LDL-lowering nutraceuticals.