1-Methylhistamine dihydrochloride is primarily used in research settings to study histamine receptors and their physiological roles. It acts as a selective agonist for the H1 histamine receptor, making it valuable for investigating allergic reactions, inflammation, and the central nervous system's histaminergic pathways. In pharmacological studies, it helps elucidate the mechanisms of histamine-related disorders, such as asthma, allergies, and autoimmune conditions. Additionally, it is utilized in the development and testing of antihistamine drugs, aiding in the identification of compounds that can effectively block histamine receptors. Its application extends to neuroscience research, where it helps explore the role of histamine in sleep-wake regulation, cognition, and neuroinflammatory processes.