I'm on pristiq (desvenlafaxine) and i've been feeling nauseous and having random pains in my neck and can't sleep i'm not sure if it's my medicine or what?

Could be medicine: In clinical studies, the most common side effects with Pristiq (desvenlafaxine) 50 mg were: nausea dizziness, sweating, constipation, decreased appetite. These are not all the possible side effects if you’re concerned about side effects, talk to your doctor.

Pristiq (desvenlafaxine): If symptoms coincided with starting or increasing the pristiq, (desvenlafaxine) yes. Review with your doc.