A Guide to Nootropic & Brain-Support Supplement Ingredients

My wife caught me at the kitchen table at eleven o'clock at night with four browser tabs open, checking whether a bacoside percentage on some other site's brain-supplement chart actually came from the paper it cited. It didn't — not exactly. The number was close enough to sound right and far enough off to be useless. That's what fourteen months of testing supplements and logging results in a spreadsheet does to a person: once you've caught one figure that doesn't reconcile, you stop trusting the rest of the page until you've checked it yourself. Old habit from thirty years of accounting. My wife says the spreadsheet has more tabs than our tax returns ever did, and she's not wrong.

So this is the ingredient sheet I wish existed when I started. Every mechanism and every percentage below is checked against the actual paper or agency page behind it, not copied off whichever site happened to rank first. Where a source didn't hold up, I said so instead of quietly leaving the number in. Where a source flat-out disagreed with what everyone repeats about an ingredient, I went with the source.

On this page
Standardization decoder for eleven nootropic ingredients with each active compound and its key standardization figure. Botanical extracts: Bacopa monnieri (bacosides A and B, 24-55% bacosides), Rhodiola rosea (rosavins and salidrosides, minimum 3% rosavins and 0.8-1% salidroside), Ginkgo biloba (flavone glycosides and terpenes, EGb 761 at about 24% glycosides and 6% terpene lactones), Lion's Mane (hericenones and erinacines, content varies between fruiting body and mycelium), Panax ginseng (ginsenosides, about 1.5-7% with a 4% benchmark), L-theanine (a free amino acid, not percentage-standardized). Cholinergics: Alpha-GPC (about 40% choline by weight), Citicoline (about 18% choline by weight), Caffeine (half-life about 5 hours), Creatine (monohydrate is the form used in most human cognition trials), Phosphatidylserine (FDA qualified health claim for cognitive dysfunction and dementia). Not medical advice.
Each ingredient's active compound and the standardization or composition figure the label should print — the label-literacy version of the tables below. This is a reference, not medical advice, and it does not say any ingredient works; the figures are about composition and dose, not proof of benefit. Embed this chart with credit to lucidwick.com — or download the image.

Standardization is the whole ballgame: alpha-GPC is about 40% choline by weight; citicoline only about 18% — so the same-size capsule delivers very different amounts of what you're actually after. And if a botanical's label doesn't print its rosavin, ginsenoside, or bacoside percentage, that number isn't a secret — it's just not on the label, and you can't dose what you can't see.

Botanical Extracts and Adaptogens

These are the plant-based ones, where the standardization percentage printed on the label is doing almost all the work — the same way the actual interest rate on a loan matters more than whatever the loan is named. I've cycled through most of these at costs anywhere from reasonable to what my wife flatly called a hobby that got out of hand. The rhodiola gummies were the low point: no rosavin or salidroside percentage listed anywhere on the bottle, six weeks logged, and not one line in the spreadsheet moved. They're in a drawer now. Below is what each of these actually is, and what the source behind each number actually says — not what the label wants you to assume.

Ingredient Primary Active Compounds Mechanism of Action Common Standardization
Bacopa Monnieri Bacosides (A and B) Antioxidant enzyme activity inhibits lipid peroxidation in the hippocampus and other brain regions; may also modulate acetylcholine release and receptor binding (NCBI). 24% to 55% Bacosides (NCBI).
Rhodiola Rosea Rosavins and Salidrosides Stress-protective effects engage the hypothalamic-pituitary-adrenal (HPA) axis (PMC); root extracts also inhibit monoamine oxidase (MAO-A and MAO-B) in vitro (PubMed). Standardized extracts contain a minimum of 3% rosavins and 0.8% to 1% salidroside (roughly a 3:1 ratio) (PMC).
Ginkgo Biloba Flavone glycosides and Terpene lactones Dose-dependent increase in cerebral blood flow; flavonoid fraction scavenges free radicals (PMC). EGb 761 extract adjusted to ~24% flavone glycosides and 6% terpene lactones (PMC).
Lion's Mane Hericenones and Erinacines Hericenones and erinacines can induce Nerve Growth Factor (NGF) synthesis in nerve cell cultures (PubMed). Hericenones occur in the fruiting body; erinacines occur in the mycelium — content varies by which part of the mushroom the extract is made from (Mycogenius).
Panax Ginseng Ginsenosides (e.g., Rb1, Rg1) Proposed adaptogen mechanism: research reviews suggest extracts affect the hypothalamus-pituitary-adrenal axis and the immune system (AAFP). Standardized to a ginsenoside content of roughly 1.5% to 7%, with 4% cited elsewhere as a key benchmark (AAFP).
L-Theanine γ-glutamylethylamide Partial co-agonist at NMDA receptors (PubMed); animal studies suggest increased brain serotonin, dopamine, and GABA levels (PubMed). Sold as a free amino acid rather than a percentage-standardized botanical extract.

Cholinergics and Metabolic Compounds

This half of the sheet reads more like a chemistry set than a garden, but the audit logic doesn't change: what's the actual compound, and does the number attached to it survive a second look. A couple of these matter for a different reason than the botanicals above. Caffeine is the one ingredient on this whole page I never had to test to know the timing on — I've been running on it since long before any of this started — and it's also the one most likely to already be sitting in your system alongside whatever else is in your medicine cabinet, which is exactly why the disclaimer below isn't just boilerplate I copy-pasted in.

Ingredient Primary Active Compounds Mechanism of Action Composition Fact
Alpha-GPC L-Alpha glycerylphosphorylcholine Choline fraction is used to produce acetylcholine, the neurotransmitter involved in focus, learning, and memory (NeuroVesa). Roughly 40% choline by weight (Nootropics Expert).
Citicoline Cytidine 5'-diphosphocholine Cytidine fraction converts to uridine, which is involved in cell-membrane synthesis (NeuroVesa). Roughly 18% choline by weight (Nootropics Expert).
Caffeine 1,3,7-trimethylxanthine Antagonizes all four adenosine receptor subtypes (A1, A2a, A2b, and A3); A2a antagonism is particularly responsible for the wakefulness effect (NCBI). Mean half-life is approximately 5 hours in healthy adults (NCBI).
Creatine Methylguanidine-acetic acid Regenerates Adenosine Triphosphate (ATP) via the phosphocreatine system — about 40 times faster than oxidative phosphorylation and 10 times faster than glycolysis (PMC). Monohydrate is the form used in most human cognition trials to date (PMC).
Phosphatidylserine Glycerophospholipid Present in neuronal membranes, where it modulates neurotransmitter release and synaptic signaling (PMC). FDA allows qualified health claims for phosphatidylserine and cognitive dysfunction/dementia (FDA).

Last verified: 2026-07-11

Disclaimer: The information on this site is based on personal experience and research for informational purposes only. It is not a substitute for professional medical, financial, or legal advice. Always consult a qualified professional before making decisions that affect your health or finances. One line item worth flagging before any of this goes in your cart: Panax ginseng doesn't mix cleanly with blood thinners like warfarin, insulin, other diabetes medications, or older antidepressants known as MAOIs — and anyone with a heart condition or arrhythmia should think twice about stacking caffeine-heavy nootropics on top of everything else in a day. Run your actual list past your doctor or pharmacist before you buy, not after. That's not me being extra cautious — that's just bad audit practice, checking the number after you've already spent the money.

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