Ingredients

One page per ingredient. Each profile covers the plausible mechanism, what human trials actually found, the dose used in that research, who should avoid it, and which products on this site contain it.

This library describes each ingredient by where it comes from, how it works and the doses used in studies — the details that help you pick the formula that suits you.

Each profile states plainly where the evidence is strong (usually micronutrient correction in deficiency) and where it is moderate (adaptogens on stress and fatigue endpoints).

All ingredient profiles

Mechanism, human trial results, dose and safety — with the evidence tier stated up front.

Maca Root — Libido and energy Maca Root Lepidium meyenii Moderate evidence Panax Ginseng — Adaptogen, erectile function Panax Ginseng Panax ginseng C.A. Meyer Moderate evidence L-Arginine — Nitric oxide precursor L-Arginine Amino acid Moderate evidence Tribulus Terrestris — Libido and sexual function Tribulus Terrestris Tribulus terrestris L. Research ongoing Zinc — Testosterone cofactor Zinc Essential trace mineral Strong evidence Vitamin D — Hormone precursor Vitamin D Cholecalciferol (D3) Strong evidence Ashwagandha — Adaptogen, cortisol Ashwagandha Withania somnifera Moderate evidence Tongkat Ali — SHBG and stress Tongkat Ali Eurycoma longifolia Moderate evidence Saw Palmetto — Prostate phytotherapy Saw Palmetto Serenoa repens Research ongoing Epimedium (Horny Goat Weed) — Icariin, PDE-5 pathway Epimedium (Horny Goat Weed) Epimedium sagittatum Emerging evidence Boswellia Serrata — Joint comfort Boswellia Serrata Boswellia serrata Moderate evidence Nettle Root — SHBG binding, prostate Nettle Root Urtica dioica Moderate evidence Ginkgo Biloba — Circulation, bleeding risk Ginkgo Biloba Ginkgo biloba L. Emerging evidence Selenium — Sperm quality, narrow window Selenium Essential trace mineral Strong evidence Cordyceps — Oxygen use, endurance Cordyceps Cordyceps militaris / sinensis Moderate evidence Reishi — Immune modulation, sleep Reishi Ganoderma lucidum Emerging evidence Fenugreek — Libido, blood glucose Fenugreek Trigonella foenum-graecum Emerging evidence

Guides in this topic

Frequently asked questions

How is evidence quality rated in these profiles?

Strong = multiple randomised controlled trials in humans with consistent direction of effect, ideally pooled in a meta-analysis. Moderate = several human trials with mixed or modest results, or consistent results in narrow populations. Limited = mainly animal or in-vitro data, or small human studies with methodological weaknesses.

Why do some ingredients work only in deficient people?

Micronutrients such as zinc and vitamin D are cofactors in enzymatic processes. Once the enzyme is saturated, adding more substrate changes nothing. That is why supplementation reliably raises testosterone in zinc-deficient men and reliably does nothing in men with adequate status.

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