Willy,
Normally the use of steroids precludes flying
duties.However steroids used to treat specific problems eg. corticosteroids for
some autoimmune diseases can be taken up to 10mg daily after a qualifying period(to ascertain how the individual reacts to the drug)and flying may commence.I doubt the CAA
would be happy about pilots using anabolic steroids in the pursuit of enhanced performance or to build muscle and I would guess if they found out they would suspend
your medical.My advice mate is don't risk it.
Regards.