Mechanisms of Action
Metabolism
The chemical processes by which the body converts nutrients into energy and building blocks.
Metabolism encompasses all chemical reactions in the body that convert food and supplements into energy (catabolism) and cellular building blocks (anabolism). Metabolic rate — the speed of these reactions — is influenced by thyroid hormones, muscle mass, age, genetics, and physical activity. In pharmacology, metabolism refers specifically to the biotransformation of substances (primarily in the liver via cytochrome P450 enzymes) into active metabolites or inactive forms for excretion. Some supplements are prodrugs requiring metabolic activation, while others are inactivated by first-pass metabolism.