SDA Labs, Diphenhydramine HCL, 25 Mg, 1000 CapsProduct Description Diphenhydramine hcl is an antihistamine that is commonly used to relieve symptoms of allergy, hay fever, and the common cold. This product works by blocking the action of histamine, a substance in the body that causes allergic symptoms. It can also be used to help nausea, vomiting and dizziness caused by motion sickness, and can induce sleep. Product Benefits Effective Relief From Allergy Symptoms. Benefits For Motion Sickness. Non