What is white oval 906?

The white oval pill imprinted with "906" is identified as Diphenhydramine Hydrochloride 25 mg, a common over-the-counter antihistamine. It is often used to relieve symptoms of Allergies, hay fever, and the common cold, such as runny nose, sneezing, and itching. Additionally, it can be used as a sleep aid due to its sedative properties. Always consult a healthcare professional before use.