Cinchona Bark

The bark of the cinchona tree is often used as a bittering agent to make bitters, tinctures, and liqueurs. 

Not to be used during pregnancy. Do not exceed recommended dose. The compound quinine may cause serious and potentially life-threatening hypersensitivity reactions in some individuals. Cinchona may cause gastrointestinal irritation; use with caution in persons with gastric or intestinal ulcers.