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.
Agmatine sulfate is a supplement form of agmatine, a compound the body makes from arginine. Human evidence is thin: one small randomized trial in sciatica-type pain, a few open-label case series, and mostly animal data for mood and exercise claims.
Curcumin phytosome (Meriva) is a lecithin-bound curcumin made to fix curcumin’s poor absorption. Here is how it compares with piperine and other forms, plus the evidence and safety.
Fadogia agrestis is a West African shrub marketed to raise testosterone. There are no published human trials; the evidence comes from a few rat studies that also reported adverse changes in testicular, liver and kidney markers. We do not recommend it.
L-citrulline is an amino acid that raises blood arginine more reliably than arginine itself. Meta-analyses show small, inconsistent exercise benefits and modest blood pressure reductions in older adults; it is well tolerated at 3–8 g a day.
Magnesium glycinate (bisglycinate) is magnesium bound to glycine. It is gentle on the stomach and now has its own placebo-controlled sleep trial, but most magnesium research used other forms. Here is what the evidence supports and how to dose it safely.
NMN reliably raises blood NAD+ in human trials, but functional benefits are modest and mixed. Here is the evidence, dosing, safety and current FDA status.
Palmitoylethanolamide (PEA) is a natural fatty acid amide sold as a dietary supplement in the US. Several meta-analyses of randomized trials suggest it reduces chronic pain, with smaller, preliminary studies on sleep and mood. It is very well tolerated.
Shilajit is a purified mineral pitch from mountain rock, rich in fulvic acids. A handful of small human trials, mostly of the PrimaVie extract at 250 to 500 mg a day, suggest modest effects on testosterone, muscle fatigue and sperm, but contamination with heavy metals is a real concern with raw products.
TUDCA is a bile acid sold as a liver and cell-stress supplement. Here is what the human trials actually tested, why the high-profile ALS results were disappointing, the doses studied, and who should avoid it.
Ubiquinol is the reduced, active form of CoQ10. Here is what the research shows on absorption, statin muscle pain, migraine and fatigue, plus dosing and safety.
