Dated 'last reviewed' stamps on YMYL: a 300-page recency study

Dated 'last reviewed' stamps on YMYL: a 300-page recency study

The question: does adding and maintaining a verifiable 'last reviewed' date — backed by actual content updates — correlate with YMYL performance, or is the date itself decorative?

A medical publisher's documented rollout: ~300 evergreen condition pages received a visible 'Last medically reviewed on [date]' stamp tied to a real quarterly review cycle, where reviewers logged changes. Pages genuinely updated (new studies cited, dosages corrected) were compared against pages where the stamp refreshed but content barely changed. Reported result over ~6 months: substantively-updated pages gained an average of 2.6 positions; stamp-only-refreshed pages gained ~0.3.

This maps to the QRG's emphasis on accurate, current information for YMYL (section 3.4) and to Google's repeated warnings against fake freshness.

Counter-evidence: substantively-updated pages received editorial attention the stamp-only pages did not — again, effort confound.

Caveat: the date string itself is almost certainly not the lever. The case suggests the *content change behind* the date matters, and a refreshed date over stale content moved nothing.

What we still don't know: whether Google detects 'fake' freshness directly, or whether stamp-only pages simply failed to improve because nothing about them actually improved. Either reading fits the data.