Artvigil 150mg contains armodafinil, a wakefulness-promoting medicine prescribed for certain sleep disorders, including narcolepsy, obstructive sleep apnea, and shift work sleep disorder. The appropriate dose and timing depend on the condition being treated and should be determined by a healthcare professional. For narcolepsy or obstructive sleep apnea, armodafinil is commonly prescribed once daily in the morning. For shift work sleep disorder, it may be prescribed before the work shift. Taking it at the wrong time can make it harder to sleep afterward, so timing is important.