What is an enzyme?
An enzyme is a protein that makes one specific chemical reaction in your body happen thousands of times faster than it would on its own.
Think of enzymes as specialized tools on a factory line. One only cuts, another only glues, another only copies. Without the right tool, the job technically could happen, but it would take years instead of a fraction of a second.
Why it matters for aging
Your body uses thousands of different enzymes. Some break down food, some build new tissue, some repair DNA, and some copy it. For example, an enzyme called POLG copies the DNA inside your mitochondria, the cell's power plants, and its occasional mistakes are a key part of how mitochondria age.
Many enzymes need helper molecules to work. NAD⁺, for example, is a helper that energy-making and repair enzymes depend on, which is why its decline with age gets so much attention.
A common myth
Taking enzyme supplements replaces or boosts the enzymes inside your cells.
Most swallowed enzymes are proteins, so your stomach digests them like food. A few digestive enzymes, such as lactase for milk sugar, can work inside the gut, but they don't reach your cells.
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Updated Nov 7, 2026 · All terms