What is the main alkaloid in cocoa besides caffeine?

Theobromine is the main alkaloid in cocoa besides caffeine.

Theobromine is a bitter compound naturally found in cacao beans and therefore in chocolate. Its name comes from the scientific name of the cacao tree, Theobroma cacao, which means “food of the gods” in Greek-derived terminology. Theobromine belongs to the methylxanthine family, the same broad chemical group as caffeine.

Chocolate generally contains much more theobromine than caffeine. The compound contributes to cocoa’s bitter taste and has stimulant effects, although it is milder than caffeine for most people. Dark chocolate usually contains more cocoa solids and therefore more theobromine than milk chocolate.

Theobromine is also why chocolate can be dangerous for dogs and some other animals. Their bodies process it more slowly than humans do. Human sensitivity varies, so the amount of stimulant compounds differs according to chocolate type, cocoa percentage, and serving size.