DeAndre Hopkins on Wednesday revealed what was in his system that resulted in his six-game suspension for violating the NFL's PED policy.
arizonasports.com
So Hopkins got popped for having .1% Ostarine in his system. He says is still investigating how that could have happened. Ostarine is a SARM, basically a newer type of steroid. SARMS are weak PEDS with potentially unknown side effects that are hard to mask from anti doping tests. It makes very little sense for pro athletes to use SARMS intentionally, but they get popped for them quite often.
From what I've seen in steroid documentaries, athletes who get popped for trace amounts of SARMS are probably regular steroid abusers. Normal steroids and SARMS are often produced in the same location. What can happen is trace amounts of SARMS get accidentally mixed with the actual steroids while they are in powder form during production. Could be from something as simple as not properly wiping down a table. This results in an athlete who regularly uses steroids, who knows how to fool anti doping tests, testing positive for a substance that they had no idea was in their body. Different PEDS stay in the body for different lengths. Some can be out of system in a few day, some will present for months. Impossible to hide something you don't know you're taking.