Hi. Welcome to HCM. Vyvnase is
Lisdexamfetamine and is used to treat attention deficit
hyperactivity disorder (ADHD) as part of a total treatment plan.Please do not take this medication in the afternoon or evening because it may cause you to have trouble sleeping. Most common side effects are nausea, vomiting, stomach/
abdominal pain, loss of appetite, dry mouth, headache,
nervousness, dizziness, trouble sleeping, sweating, weight loss, irritability, and
restlessness.These side effects may appear during the first few weeks. Normally these side effects will disappear or will not cause enough discomfort to contact your doctor. Prozac u have stopped taking and it has no role to play here.Fluctuation in period is less likely due to vyvnase, it may be due to other reason which u should get evaluated by your treating doctor. Just for precaution, If incase u experience any seizure (fits) contact your doctor immediately. Wish u good health