Citron (Citrus medica) has a long history of use in traditional medicine systems, particularly in parts of Asia and the Mediterranean. In various folk remedies, citron peel, fruit, or extracts have been used to help with digestive complaints, coughs, and as a mild sedative for sleep disturbances, including insomnia. Ancient and medieval herbal texts sometimes mention citron as an ingredient in calming infusions or preparations used at bedtime, likely due to its pleasant aroma and mild sedative properties attributed in traditional lore. However, these uses are largely based on anecdotal or empirical tradition rather than systematic studies.

Modern scientific evidence supporting the use of citron specifically for insomnia is lacking. While some citrus fruits and their essential oils (such as those from oranges or bergamot) have been studied for mild anxiolytic or sedative effects, citron itself has not been the subject of rigorous clinical research regarding sleep or insomnia. No major pharmacological studies have isolated active constituents in citron with proven sleep-promoting effects in humans. Therefore, current use for insomnia is primarily justified by traditional uses rather than scientific validation.