While Hydroxyzine and Benadryl (diphenhydramine) are both antihistamines, they are not the same medication. Hydroxyzine is often prescribed for anxiety, allergies, and sleep issues, and is available only by prescription. Benadryl, on the other hand, is an over-the-counter allergy medication primarily used for short-term relief of allergic reactions and cold symptoms. This guide explains the key differences in their uses, strengths, side effects, and availability, helping you understand which might be more appropriate for your needs.