Sources Policy

Each kind of claim has its own kind of source. Peer-reviewed research supports scientific statements, legislation and regulators support legal statements, standards bodies support laboratory standards, and a product’s own published documents support statements about that product. Every source is numbered on the page and linked where possible.

Updated 4 October 2026Part of Editorial policy

Which source supports which claim

Source types we use
Claim type	Preferred source	Example
Science and health	Peer-reviewed studies and reviews, read in full where available	Randomised trials indexed on PubMed
UK law and regulation	Legislation and official regulator guidance	legislation.gov.uk, FSA, MHRA, ASA
Laboratory standards	The standards body or accreditation body	ISO, UKAS
A specific product	The product’s own published documents, labelled brand-supplied	A batch COA published by the brand

What we don’t use as evidence

Seller marketing for scienceA product page can show what a brand claims, never that a claim is true.
Forums and social postsNot used as evidence for facts.
Abstracts aloneWhere a full paper is available, we read the methods.
Unverifiable figuresIf we can’t trace a number, we don’t publish it.

Secondary sources

Occasionally a reliable secondary report is the best available record of a primary decision, such as trade press reporting an advertising ruling. We label these as secondary and replace them with the primary source when it becomes available.

How citations appear

Citations are numbered in the text and listed at the end of each page with authors, title, publication, year and a link. How research is found and summarised is described on how we find & summarise research.