Vicks NyQuil is a brand of over-the-counter medication manufactured by Procter & Gamble intended for the relief of various symptoms of the common cold. All medications within the NyQuil imprint contain sedating antihistamines; they are intended to be taken before sleep. Its daytime counterpart is antihistamine-free DayQuil, formulated to avoid drowsiness. NyQuil is also used as a sleep aid.[1] NyQuil was first marketed in the United States in 1966.[2][3]