The Prohibited List identifies substances and methods prohibited in-competition, at all times (i.e. in-and-out-of-competition) and in particular sports. 
Substances and methods are classified by categories (e.g. steroids, stimulants, masking agents). 
The list is updated annually and goes into effect January 1 of each year.
The 2019 Prohibited List [EN]
The 2020 Prohibited List [EN] [FR] [ES] [DE] [PR] [AR]
The 2021 Prohibited List  [all documents on WADA page]

Summary of the Major Modifications and Explanatory Notes [EN]
You can find the mobile-friendly version of the 2020 Prohibited List HERE.
Do you have more questions? See the WADA’s Prohibited List Q&A.

WHAT DOES THAT MEAN FOR AN ATHLETE?
Each athlete is responsible – strictly liable – for anything found in his/her body, regardless of how it got there or whether there was any intention to cheat.

If you are charged with having committed an Anti-Doping Rule Violation, it is not necessary to prove intent, fault, negligence or knowing use on your part. For example, the following are not valid defences: that the prohibited substance was not listed on the label or that your coach gave you a substance.

See WADA’s Q&A on Strict Liability in Anti-Doping

WHAT YOU, AS AN ATHLETE, SHOULD DO?

• Be aware of the annual changes to the Prohibited List;
• If you are using supplements, do your research to check if they contain prohibited substances;
• Before taking any medication, make sure to check with your prescribing physician that it does not contain a prohibited substance;
• Check that the medication does not contain any substances that would fall within a general category that is prohibited. An online database that can be used is  GlobalDRO
• Inform your doctors and your medical personnel that you need to abide by the Anti-Doping Rules. If you use Prohibited Substances for therapeutic ends, make sue you obtain a Therapeutic Use Exemption (TUE) at the relevant time.