Bird peppers are very hot chilis that are, as the color suggests, high in vitamin A. Cayenne is good for the eyes and circulation. It relieves congestion and promotes metabolism. In Hawaii, it is used to treat ulcers and many people use it for dyspepsia. It is very stimulating so attention should be put on potentially dramatic changes in peristalsis.
Cayenne vitiates kapha and vata but may aggravate pitta.