If you've paid attention in chemistry class, you know acids can have pretty nasty effects on living things. Especially on things like teeth which lead people to purchase supplements like Dentitox Pro.

Azelaic acid is a type of acid that's found in some grains like rye, wheat, and barley. It's naturally produced by Malassezia furfur (also known as Pityrosporum ovale), a yeast found on healthy skin.