Verywell In shape's content is for informational and educational functions only. Our Web site is not meant to be considered a substitute for Skilled professional medical advice, diagnosis, or treatment. Below ultraviolet light-weight, the quinine in tonic water fluoresces, as noticed with this bottle of copyright Dry tonic water. Tonic https://blndwater.com/products/blnd-lemon-and-mint-tonic-water-250ml