Cayenne is normally a perennial plant, but it is an annual outside of tropical regions. The plant grows from 2 to 6 feet in height and bears tapered, egg-shaped leaves. Cayenne flowers from April to September, with white-to-yellow blossoms, and bears straight, oblong fruit which varies in size and is red or yellow in color. The hot-tasting fruit (or pepper) is used around the world as a food and a spice, as well as for health purposes.
The primary active constituent in cayenne peppers is a compound called capsaicin. This is the substance that makes peppers taste "hot." Cayenne also contains vitamins A and C, carotenoids, and volatile oils.
Cayenne pepper can be used liberally in the diet and can also be taken in capsule form. The potency of cayenne capsules is measured in heating units (HU), and is usually listed on the label. The acceptable dosage varies widely, as the body develops a tolerance for capsaicin. New or infrequent users of the herb may experience gastrointestinal discomfort. These people may wish to start with a small dose and increase the amount as their tolerance develops. Cayenne supplements are not recommended for people with active gastric ulcers because capsaicin may aggravate their condition. Topical formulations usually contain from 0.025 to 0.075 percent capsaicin, and can be applied to affected areas up to four times daily. Some users experience a burning sensation upon topical application of capsaicin, but this effect usually fades over time. Caution should be taken to avoid contact with the eyes or broken skin, which may be extremely irritated by capsaicin.