Most health advice cites nothing, or cites everything as though it were equally certain. This is the whole library the app plans from, with the rating on each one. 122 of the 204 are rated Mixed or weaker — you can filter to them and read exactly what we are unsure about.

All 204 practices.

What the letters mean

AStrong
Repeatedly tested in people, with results that agree. 15 practices.
BGood
Solid human studies, with some room left for argument. 67 practices.
CMixed
Reasonable evidence, smaller studies, or results that conflict. 73 practices.
DThin
Early or indirect evidence. Worth trying, not worth promising. 41 practices.
EPractice
No trial behind it. Widely used, and openly labelled as experience rather than proof. 8 practices.

Why we publish the weak ones

A library where everything is excellent is a library that is not rating anything. The grade is only worth reading if it can come out low, so the low ones are here, filterable, with the same detail as the rest. If a practice is rated E it means we found no trial behind it — it is widely used and we are telling you it rests on experience rather than proof, which is different from saying it does not work.

What this is not

It is not medical advice and it is not a recommendation for you personally. A rating describes the strength of the published research, not whether a thing suits your body, your history or your medication. The safety notes say what a practice will not do and who should skip it; 171 of the 204 carry one. Where something touches alcohol, sleep or your head, talk to a doctor rather than a library.

Written up in full

Six of these get a page of their own, because they are the questions people actually search for. Each one leads with its grade, including the ones that are not flattering.

See how these get planned into a week →