The blue oval pill marked Y 20 l has been identified as Alprazolam 1 mg. Alprazolam is classified as a benzodiazepine. Y 20 pills are used to treat anxiety disorders and panic disorders, which means sudden, unexpected bouts of extreme fear and anxiety. It works by reducing the abnormal excitability of the brain. The recommended dose of the Y 20 pill for adults varies depending on its use. The dose usually starts small and is increased as needed