Most sleep gear is sold on feelings. We publish the numbers instead.

There is a specific problem with this category. The devices measure real signals — pulse waveform, skin temperature, motion, respiration — but they infer the thing you actually care about. A ring does not see brain waves. It estimates sleep stages from proxies, and the best independent result anyone has published for a consumer ring is 79% agreement with clinical polysomnography on four-stage classification. That is genuinely good. It is also not the same as truth, and almost nobody selling these things will tell you the difference.

So that is the editorial line here: take the measurement seriously, take the marketing sceptically, and be explicit about the gap between them.

Supplement reviews. This site does not cover pills, tonics or "vitality boosters." The category is dominated by products whose evidence base is a landing page, and reviewing them honestly would mean writing the same negative conclusion two hundred times.

Numbers we did not collect. Where a review is still in its test window, the page says so and shows no results. Empty is better than invented.

Undisclosed commercial links. Some outbound links to retailers earn a commission. Every page carrying one says so before the link appears, and no merchant has ever been given review approval, copy approval, or advance sight of a conclusion. The full policy is on the editorial policy page and the commercial arrangement is set out at disclosure.

Medical advice. Nothing here is a diagnosis or a treatment recommendation. Blood panels in particular are useful precisely because they produce results a clinician should look at.