The 2021 Prohibited List, in force from 1 January 2021; the document determining which substances and which methods were prohibited for athletes during that period.
| In force from | 1 January 2021 |
| Publication | World Anti-Doping Agency — 2021 List |
| Structure | International Standard — Prohibited List, 2021 edition |
| Status | Superseded — replaced by the 2022 List |
The Prohibited List is one of the binding International Standards of the world anti-doping system and determines which substances and which methods are prohibited. Its structure has three parts: substances prohibited at all times (the S categories, together with the M methods), substances prohibited in-competition only, and substances prohibited in particular sports (category P). Alongside the List sits the Monitoring Programme: substances kept under observation but not treated as prohibited. The World Anti-Doping Agency reviews and publishes this List at least once a year.
In every doping case, the first question is whether the substance detected was prohibited under the List in force on the date of sample collection — and because this List changes every year, the answer depends on the edition governing that day; for that reason the previous editions are retained on this page. For the team physician, distinguishing "prohibited at all times" from "prohibited in-competition" and checking the Monitoring Programme is likewise essential before prescribing any medication. The official text is published in English and French, and in the event of any conflict the English text prevails.