The most common ones are headache, symptoms of upper respiratory tract infection such as runny nose, nausea, nervousness, insomnia, back pain, diarrhea, hearburn.  Other Provigil side effects which may occur are dry mouth, loss of appetite, flushing, diarrhea, tremors and sweating and shakiness.

Unusual Provigil side effects are anxiety and depression, confusion, hallucinations, fast pulse, palpitations, muscle spasms, blood in the urine, allergic reactions such as itching or rashes or difficulty breathing.

A rare but potentially life-threatening hypersensitivity phenomenon is the Stevens-Johnson syndrome (which can be seen in exposure to other drugs as well such as sulfonamides), which comes on with an initial rash, but which progresses to a situation affecting the skin and mucous membranes causing separation of large tracts of the upper layer of skin known as epidermis from the dermis, causing symptoms such as severe ulceration in the mouth.