Doctor prescribed omega3 for my cousin 5 years old she took it for 6months should stop it now? and is it dangerous if it's taken for long time

Not dangerous: Omega 3 fatty acids are important fats in one's diet. They are one of the healthy fats that help fight elevated cholesterol levels. It is not dangerous, as most of us receive these fats as part of of regular diet: ie, fatty fish, such as salmon. You should suggest that your cousin's mother should discuss with his pediatrician the reason for initiating the use of the omega 3s and what the endpoint