Valproate side effects may include:Gastrointestinal problems such as nausea, vomiting, and heartburnHeadachesVisual disturbancesRinging in the earHair lossWeight gain (a significant problem with valproate)AgitationOdd movementsMenstrual irregularities and a higher risk for polycystic ovary syndrome (PCOS)Birth defects when taken by pregnant women during the first trimester (valproate has the most