Rivium Glossary
Plain-language definitions grounded in published research—not promises.
Akkermansia muciniphila is a species of bacteria that naturally lives in the healthy human gut — specifically in the mucus layer lining the intestine, where it feeds on mucin (the main component of mucus). It typically makes up a few percent of an adult's…
Read definition →Bioavailability is the proportion of a nutrient or compound that actually reaches your bloodstream in an active form after you take it — not just the amount printed on the label. If a capsule contains 500 mg of an ingredient but your body only absorbs and…
Read definition →Catechins are a family of plant polyphenols (a type of antioxidant compound) found abundantly in green tea. The most studied and most abundant is EGCG (epigallocatechin gallate) . When people talk about green tea's antioxidant or metabolic effects, they're…
Read definition →CFU stands for colony-forming units , the standard way to measure the number of live, viable microorganisms in a probiotic. One CFU is a single microbe (or cluster) capable of growing into a colony. A label reading "10 billion CFU" means the product is…
Read definition →The Daily Value (DV) is a reference amount of a nutrient set by the FDA for use on nutrition and Supplement Facts labels. On the label you usually see it as % Daily Value (%DV) — the percentage of that reference amount provided by one serving. It's…
Read definition →Elemental magnesium is the amount of actual magnesium in a supplement, as opposed to the weight of the whole magnesium compound . Magnesium is always bound to something else — glycinate, citrate, oxide, etc. — and that carrier adds weight. The elemental…
Read definition →A magnesium salt in which magnesium is bound to the amino acid glycine.
Read definition →NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. It's one of the most essential molecules in metabolism — a helper that many enzymes require to function. It exists in two interchangeable forms, NAD+ (oxidized) and NADH…
Read definition →NMN (nicotinamide mononucleotide) is a molecule the body uses as a direct precursor to NAD+ , the essential coenzyme involved in energy metabolism and cellular repair. Because NAD+ levels appear to decline with age, NMN became one of the most popular…
Read definition →A prebiotic is a substance — usually a type of dietary fiber — that your own body can't digest, but that feeds the beneficial microorganisms in your gut . Where a probiotic adds live microbes, a prebiotic is the food that helps the microbes you already…
Read definition →A probiotic strain is a specific, genetically defined variant of a beneficial microorganism, identified by three levels: genus, species, and strain designation — for example, Lactobacillus (genus) rhamnosus (species) GG (strain). The strain is the most…
Read definition →A proprietary blend is a group of ingredients listed on a Supplement Facts panel under a single combined name and total weight , without disclosing how much of each individual ingredient it contains. US labeling rules allow this: the brand must list the…
Read definition →A standardized extract is a botanical (herb) extract processed so that it contains a guaranteed, consistent amount of one or more marker compounds — usually expressed as a percentage. For example, "green tea extract standardized to 50% EGCG" means half its…
Read definition →The Supplement Facts panel is the standardized, FDA-required information box on a dietary supplement — the supplement equivalent of the "Nutrition Facts" label on food. It's the regulated, factual part of the packaging, as opposed to the marketing claims…
Read definition →Third-party testing is independent verification of a supplement by an outside lab or certifier that has no financial stake in selling the product. Because supplements in the US aren't approved by the FDA before sale, third-party testing is one of the main…
Read definition →The Tolerable Upper Intake Level (UL) is the highest average daily intake of a nutrient that is unlikely to cause harm to almost everyone in the general population. It's set by nutrition-science bodies as part of the Dietary Reference Intakes. Think of it…
Read definition →