How digestive enzymes work

Enzymes are proteins that speed up chemical reactions in the body. In digestion, their job is to break food down into pieces small enough to be absorbed. Your body makes its own digestive enzymes in the mouth, stomach, pancreas and small intestine. Supplemental enzymes, often sourced from plants or fermentation, are taken with food to add to that process.

Each enzyme is specialised — it works on one kind of food component. Here is what the common ones target.

Enzymes can only work on food they come into contact with. That is why they are usually taken at the beginning of a meal, so they mix with the food as you eat. Taking them long before or long after eating gives them less to work on. Always follow the directions on the label of the product you use.

A useful enzyme label names every enzyme individually and gives its amount, ideally with an activity unit as well. Activity units — such as HUT for protease or ALU for lactase — tell you how much work the enzyme can do, which weight alone does not. Be cautious of "proprietary blends" that list ingredients under a single total, because you cannot see how much of each is inside.

If a label won't tell you how much of each enzyme is inside, it's fair to ask why.

Digestive enzyme supplements are food supplements, not medicines. They are not intended to diagnose, treat, cure or prevent any condition, and they do not change how your GLP-1 medication works. If you have ongoing digestive symptoms, the right first step is a conversation with your doctor — see how GLP-1 medication affects digestion for when to call.

Our Digestive Enzymes list all ten enzymes with amounts and activity units, alongside ginger root extract and vitamin B6. You can read about the research behind each ingredient on our science page.