Dyanavel XR is a prescription drug used to treat Attention Deficit Hyperactivity Disorder (ADHD). Dyanavel XR belongs to a group of drugs called nervous system stimulants, which work by changing the amounts of certain chemicals in the brain. This medication is a solution taken once per day, either with or without food. Common side effects include dry mouth, decreased appetite, dizziness and weight loss. Do not drive or operate machinery until you know how Dyanavel XR affects you. Since Dyanavel XR is available as an oral suspension, it is a great ADHD option for children who cannot swallow pills or capsules. Plus, the oral suspension is extended-release meaning children only have to take it once a day.