This is our library of nootropic ingredients. Each guide explains what the ingredient is, what human research actually shows (and where it’s thin), the doses used in clinical studies, side effects, drug interactions and how to buy a quality product. Every health claim links to its source, usually PubMed or the NIH Office of Dietary Supplements.
New to nootropics? Start with What Are Nootropics?, then browse by goal below.
Nootropic Ingredients By Goal
GoalIngredients To Read About
Calm Focus And StressL-Theanine, Rhodiola Rosea, Ashwagandha, Saffron, Kanna
Attention And Mental EnergyCaffeine, Citicoline, L-Tyrosine, Panax Ginseng, Creatine
Memory And LearningBacopa Monnieri, Phosphatidylserine, Ginkgo Biloba, Huperzine A, Alpha-GPC
Long-Term Brain HealthLion’s Mane, B Vitamins, Maritime Pine Bark, Uridine
Sleep And RecoveryMagnesium L-Threonate, Apigenin, L-Theanine
Energy, Vitality And HormonesTongkat Ali, Panax Ginseng, Rhodiola Rosea
Popular Ingredient Comparisons
Alpha-GPC Vs Citicoline
NALT Vs L-Tyrosine
Phosphatidylserine Vs Phosphatidylcholine
Suntheanine Vs L-Theanine
Ashwagandha Vs Rhodiola
L-Theanine And Caffeine
How We Evaluate Ingredients
We weight human randomized controlled trials and meta-analyses above animal and cell studies, compare commercial doses with the doses used in research, and call out industry funding and small sample sizes. Ratings run from Strong to Preliminary. Nothing here is medical advice. Please read our medical disclaimer and talk with your doctor before starting a supplement.
Kanna (Sceletium tortuosum) is a South African succulent whose alkaloids act on serotonin reuptake and PDE4. A handful of small Zembrin trials suggest modest anti-stress and cognitive effects, but it should never be combined with serotonergic drugs.
L-theanine is a calming amino acid from tea. Here is what human trials show for stress, sleep and focus, how much to take, and how safe it is.
L-tyrosine is an amino acid the brain uses to make dopamine and norepinephrine. Human studies suggest it helps working memory hold up under acute stress, but it does little when you are already rested and comfortable.
Lion’s mane mushroom is a popular nootropic with plenty of animal and cell research on nerve growth factor, but only a handful of small human trials. Here is what they show, how much to take and how to choose a product.
Magnesium L-threonate (Magtein) is marketed as the brain-penetrating form of magnesium. Here is what the animal and human studies show, how much elemental magnesium you actually get, and how it compares with magnesium glycinate for sleep.
Maritime pine bark extract is a proanthocyanidin-rich antioxidant extract best known as Pycnogenol. Small studies suggest benefits for attention and jet lag, but a Cochrane review rates the overall evidence as very low certainty.
Panax ginseng (Asian or Korean ginseng) is a classic adaptogen with small, mixed evidence for mental performance and fatigue. Here is what the trials show, how ginseng extracts are standardized, and who should be careful with it.
Phosphatidylserine (PS) is a membrane phospholipid studied mainly for memory in older adults and for blunting cortisol during physical stress. Here is what the trials show, how to dose it and how bovine and plant PS differ.
Rhodiola rosea is an adaptogenic root studied mainly for stress-related fatigue and burnout. Small trials are encouraging, but most have quality problems, and many products are adulterated or underdosed.
Saffron extract is one of the better-studied herbal supplements for low mood. Here is what the meta-analyses show, how it compares with antidepressants, the doses used (28–30 mg), and its safety limits.
