Board Thread:General Discussion/@comment-8870433-20131205200627/@comment-6881629-20151114183809

Being a werewolf binds you to Hircine, it plays a part in the end of the Companions questline. The Companions are the lucky ones really at least they have control over it, others can't control when they transform or what they might do during the time (see the quest Ill Met by Moonlight).