Aren't there all sorts of side effects to heavy steroid (ab)use, like problems controlling aggression? Seems like a dumb idea especially for defense oriented players.
As long as Thomas Müller doesn't grow Henry Cavill's body suddenly, I'm not convinced there is something unusual for top tier football going on here.
Müller-Wohlfart is a quack, but regardless of his practices: He's either being stupid or willfully ignorant when he says: " It would make no sense to bulk up in football [with PEDs]—the muscles would become too heavy."
As if the point of PEDs was to "bulk up". The sports with the most doping-scandals, sports like cycling or cross country skiing, are all about endurance and being able to go harder for a longer period of time. Anyone trying to tell you that football players wouldn't profit from being able to train harder, regenerate quicker and endure pyhsical stress for longer is a bullshit merchant.
It'd be naive to think that top athletes, no matter the sport, aren't trying to get an edge all over the world.
Several points in here, PED effects, Reaction of the football authorities and establishment, etc.
preamble:
by no means are only endurance sports notorious for PED abuse, although of course they are prominent; Power-hungry sports like martial arts of all sorts, weightlifting, etc are possibly even more notorious and there's been countless cases. In general, PED abuse is more common in sports that put physical attributes above skill. Given cyclings exposure to public and past scandals, one could say that the quality level and frequency of testing especially in cycling is currently higher than in any other sport today. Even amateur cyclists can only laugh about the state of pro football PED checking. Now go ahead and count the money involved. One could run a Pro cycling team on the money a 2nd league team spends on 1-2 players per year.
Müller-Wolfahrt: The fact that MW associates PED with stuff to "bulk up" shows he's not really into the matter, bacuse it is BS. Which kinda speaks for him but also is odd because his career started as assistant to a now notorious witch doctor, but whatever... Fact is, even though he has many adversaries if not enemies in the trade and accusations have been made frequently, none of these proved to have any substance as of today.
There are PED for everything, bulk up, endurance, max power, regeneration... Many have combined effects, as the more complex modern stuff, which is why some of them are used in a carefully scheduled combination because the effects support each other. See "Icarus" on Netflix for examples, its about cycling but that part applies wherever.
The denial about the use of PED in football by everyone involved in the business is a different matter. IMO football is "too big" as to let a scandal of cycling/festina/dr fuentes proportions ever see daylight, because the impact would be too grave right up to open civil war in some countries
Goretzka and Steroids: Steroids are just about the most easy PED to prove in a simple test. That and the fact it only marginally helps to be more bulky on a football field means he would have to be very stupid indeed to risk that to look nicer for the ladies. He doesn't strike me as being exceptionally stupid.