Definition

A dietary supplement is legally defined in the UK as a food product intended to supplement the normal diet. This article explains the regulatory definition, what categories exist, how efficacy claims are evaluated, and what distinguishes evidence-based supplementation from marketing.

The term 'dietary supplement' has a specific legal definition under UK and EU food law that determines what claims manufacturers can make, what safety requirements apply, and how products should be labelled. This article explains the legal definition, how it differs from food and medicines, what the regulatory framework means for consumers, and how to evaluate supplement claims against an evidence standard.