Athletes, like all others, may have illnesses or conditions that require them to take particular medications. If the medication an athlete is required to take to treat an illness or condition happens to fall under the prohibited list, a therapeutic use exemption may give that athlete the authorization to take the needed medicine. Criteria for granting a therapeutic use exemption are 1.) The athlete would experience significant health problems without taking the prohibited substance or method, 2.) The therapeutic use of the substance would not produce significant enhancement of performance, and 3.) There is no reasonable therapeutic alternative to the use of the otherwise prohibited substance or method. Note hormone replacement therapy (HRT), . supplementing with prescribed testosterone in any form to raise testosterone levels due to natural decreases that occur with aging (even if to just elevate levels to within ‘normal’ ranges), is NOT considered a medicinal exception. Persons using HRT would not be eligible for WPA/NANBF/IPE competition.
In February 2017, American triathlete Beth Gerdes was given a 2-year suspension for presence of ostarine, and American triathlete Lauren Barnett was given a 6-month suspension for the presence of Ostarine. Both triathletes claimed contamination from salt tablet supplements. Lauren Barnett was able to provide tablets and sealed bottle tablets which both tested positive for contamination, thus only the 6-month suspension. The 2-year suspension still stands for Beth Gerdes who provided tablets for testing, but tests showed only low levels of ostarine not high enough to confirm the finding. 
Drugs can be added and removed from this list by WADA annually, although not all of the banned substances are explicitly named. Caroline Hatton, PhD , a sports anti-doping science consultant, told in a Mar. 12, 2010 email that "A key concept in prohibited lists is that they avoid being finite. Instead of listing all banned drugs one by one, they list entire drug classes and name drugs merely as examples. This is to keep users who took designer drugs from claiming that they didn't break the rules because the drugs they took weren't listed."