Our method

How we write, check and correct.

A health topic calls for transparency about method. Here is how our content is produced, where our figures come from, how our calculators work, and what our tools do not do.

How our content is written and reviewed

  • Our guides are written by the editorial team from identified public sources, then reviewed by a human before publication.
  • When a health professional has reviewed a piece, their name and role appear at the top of the article, on a "Reviewed by" line. Otherwise the content stays attributed to the editorial team: we never invent an author or a reviewer.
  • Every guide carries a publication date and an update date. We correct a piece as soon as a newer or more reliable source calls for it.

How we choose our sources

  • We rely first on public-health authorities and systematic reviews: the World Health Organization, the UK NHS, the US CDC, Cochrane reviews, and France's Tabac info service and Haute Autorité de santé.
  • Any figures shown are population averages, given for information only, and always tied to their source.
  • When a figure has no verifiable source, we do not invent one: we flag it as missing rather than state a doubtful number.

How our calculators work

  • Each calculator shows its formula on its own page: you can check the calculation, not just the result.
  • All calculations run in your browser. Nothing you enter — number of cigarettes, price, quiz answers — is sent to our servers or stored.
  • Our audience measurement records that an action happened (a result was shown, a quiz was completed), never the values you entered.

What our tools do not do

  • They make no diagnosis and do not replace advice from a health professional.
  • They prescribe no treatment and recommend no nicotine-replacement dose: that is for a doctor or pharmacist.
  • They are not medical devices, and they are not intended for minors.

Report an error

Does something look inaccurate or out of date? Write to us: we check and correct. Being transparent about our mistakes is part of the method.