The league, in announcing the suspension, classified the drug as performance-enhancing.
Players often blame positive tests on misunderstandings or worse, and sometimes they are right.
The league holds players responsible for what goes into their bodies.
Moffitt is on injured reserve, so he cannot play this season anyway.
The four-game suspension begins now and will end after Week 17.
The suspension will require Moffitt to forfeit his pay for the remaining four games of the season. Moffitt's salary for the season was $375,000. Players get paid weekly over 17 weeks. Moffitt will lose four-seventeenths of his base salary. That works out to $88,235.29 in this case.
A second positive test would result in a minimum eight-game suspension.
I'll update with additional details.