Bioavailability
ProductionAlso known as: Absorption rate, Bioavailable form
The proportion of an ingredient that enters the bloodstream and is available for biological activity.
What It Means
Bioavailability measures how much of an ingested ingredient actually reaches systemic circulation and is available to produce its intended effect. It is affected by the ingredient's chemical form (e.g., magnesium oxide vs. magnesium glycinate), the dosage form (capsule, tablet, liquid), the presence of enhancers or inhibitors (piperine enhances curcumin absorption; calcium inhibits iron absorption), and individual factors like gut health and genetics. Technologies like liposomal delivery, chelation, and phytosome complexes aim to improve bioavailability but add cost and complexity. Bioavailability is typically measured through pharmacokinetic studies comparing blood levels over time.
What It Is Not
Bioavailability is NOT the same as potency. A product can contain the full labeled amount of an ingredient (high potency) but deliver very little to the body (low bioavailability). Similarly, 'bioavailable' marketing claims do not always mean the product has been tested in humans — some are based on in-vitro studies or animal models, which may not translate to human absorption.
Related Categories
Need Help Understanding Compliance?
Our directory connects you with manufacturers and labs that meet these standards.