The drug in question is said to be Clenbuterol. This is typically used for people with respiratory conditions and is neither a steroid or a hormone according to anabolic.co. It works in much the same fashion as the more popular albuterol. Clenbuterol is a popular drug among body builders and athletes for its ability to help cut weight and body fat by increasing the body's metabolism, which is why it is often listed as "performance enhancing."
Flanagan further tweeted that General Manager Dayton Moore stated Mondesi tested positive through an "innocent mistake" most likely due to a case of taking the wrong medicine with a cold. The medical benefits of the drug do not seem conducive to much of a performance boost for an athlete like Mondesi making this explanation at least somewhat palatable.
His suspension was reduced from 80 games to 50 games after he showed proof that he was given the drug through cold medicine.
Mondesi was listed as the #27 prospect in all of baseball prior to the 2015 season. The 20 year old right handed short stop was having a solid year for AA Northwest Arkansas with a slash line of .250/.304/.462 and 5 homeruns. His bat has been behind his glove so far in his young career, but he was beginning to show some pop at the plate this season, already nearly matching his homerun total from all of 2015 and increasing his offensive numbers across the board.
Per league rules, the positive test will also render Mondesi Jr. ineligible for the 2016 postseason. This means he will be unable to join the Royals in the playoffs as he did last season when he became the first player in MLB history to make his MLB debut in the World Series.
UPDATE: Jesse Sanchez is stating that Mondesi Jr. WILL be eligible for the 2016 postseason
Here is Mondesi Jr's press release regarding his suspension per 610 Radio's facebook page:
Episode 16 now up for your listening and downloading pleasure. Go get you some. Episode 16 - RoyalsBlue.Com Podcast