glycyrrhizin

Glycyrrhizin is about fifty times sweeter than sugar and is best known as the flavor of licorice. It is a natural extract of the roots of the licorice plant. If the standards used for synthetic compounds known to be toxic in high doses were applied, the maximum allowable daily intake would be at most a few sticks of black licorice. Am I saying you shouldn't eat more than a few pieces of licorice a day? No, I'm saying that glycyrrhizin in larger doses in clearly toxic, and if the safety margins typically applied to synthetic compounds were applied to it, that's what the official recommendation would be. Do with that information what you will. Because it's a natural extract that has not yet been successfully challenged, there are no legal restrictions on how much glycyrrhizin may be in a food. […] This licorice is advertised to be particularly strong, which means it has a particularly high concentration of glycyrrhizin. […] "Red licorice" is just a marketing term; it's not really licorice at all. The artificial strawberry flavors in this candy are unrelated to the glycyrrhizin in true black licorice, so you can eat as much as you like.

2014, Theodore Gray, photography by Nick Mann, Molecules: The Elements and the Architecture of Everything, 2018 Paperback Edition, pages 178-179