Supplement glossary
Decoded labels and stripped-of-marketing definitions. Linked from every guide; reference it when a bottle says something you don't recognize.
Science
Form
Capsule
A two-piece shell filled with powder or granules, made of gelatin or plant cellulose.
Chelated
A mineral bound to an amino acid carrier, usually for better absorption.
MK-7
The longest-lasting form of vitamin K2, with a half-life of around 3 days.
Softgel
A soft gelatin capsule that holds a liquid or oil-based fill.
Tablet
A dose of powder compressed into a solid pill, often with binders and a coating.
Shopping
Certificate of Analysis
A lab document showing what's actually inside a specific product batch.
Cost per serving
Price ÷ servings per container — the only fair way to compare two bottles of different sizes.
NSF Certified
A third-party certification from NSF confirming a product's contents match its label and meet contaminant limits.
NSF Certified for Sport
An NSF program that additionally screens supplements for substances banned in competitive sport.
Third-party tested
Testing done by an independent lab rather than the manufacturer itself.
USP Verified
A voluntary third-party mark from U.S. Pharmacopeia confirming a supplement's identity, potency, and purity.
Dose
Elemental
The actual amount of a mineral in a compound, ignoring the weight of the carrier salt.
Elemental magnesium
The actual magnesium content of a compound, ignoring the carrier salt.
EPA & DHA
The two active long-chain omega-3 fatty acids in fish and algae oil.
IU
International Unit — a legacy potency measure for vitamins A, D, and E.
RDA
Recommended Dietary Allowance — the daily intake estimated to cover ~97% of healthy adults.
Serving size
The number of pills the label counts as one dose — which may be more than one.
Servings per container
How many doses a bottle holds — count divided by serving size, not the pill count.
Tolerable Upper Intake Level
The highest daily intake of a nutrient considered unlikely to cause harm — the ceiling, not a target.