Methodology & Disclosures

Nutrient Criterion is an independent aggregator. We research, compare, and link to vitamins, herbs, and functional mushrooms offered by third-party merchants. We do not manufacture, warehouse, or sell products. When you click a product link, you leave our site and complete any purchase directly with the merchant.

Nutrient Criterion participates in affiliate programs. When you purchase through certain links on this site, we may earn a commission at no additional cost to you. These relationships are disclosed on every page via the top banner and near individual links where appropriate.

Affiliate compensation does not influence our evaluation criteria, scoring, or ranking order. We do not accept payment for preferential placement or favorable reviews.

Comparisons use a consistent, publicly stated set of factors:

• Third-party testing & documentation — Presence and quality of Certificates of Analysis (COAs), NSF/USP certifications, or equivalent independent testing.
• Label transparency — Clear disclosure of form, elemental amounts, standardization (for herbs and mushrooms), and inactive ingredients.
• Price per effective serving — Calculated cost based on labeled dose.
• Vendor reliability signals — Shipping practices, return policies, and history of accurate labeling where information is available.
• Form quality — Preference for well-studied forms when evidence supports it.

We rely on publicly available information. We do not perform independent laboratory testing ourselves at this stage.