WADA, in an undated FAQ, "Therapeutic Use Exemption," accessed on Apr. 26, 2021 and available at wada-ama.org, stated:

“Athletes, like all people, may have illnesses or conditions that require them to take particular medications or undergo procedures. If the medication or method an athlete requires to treat an illness or condition happens to fall under the Prohibited List, a Therapeutic Use Exemption (TUE) may give that athlete the authorization to take the needed medicine or method. TUEs are granted according the International Standard for TUEs (ISTUE), a document outlining the conditions, the stakeholder responsibilities and the TUE process…

The criteria are:

–The athlete would experience significant health problems without taking the prohibited substance or method;
–The therapeutic use of the substance would not produce significant enhancement of performance;
–There is no reasonable therapeutic alternative to the use of the otherwise prohibited substance or method;
–The requirement to use that substance or method is not due to the prior use of the substance or method without a TUE which was prohibited at the time of use.
For the TUE to be granted, all four criteria must be met.”

Apr. 26, 2021