Betel Leaf Stains from years of chewing the leaves. It is said that a woman is not ready to marry until she has such stains, indicating that she is old enough, mature and ready. The leaves are chewed together in a wrapped package along with the areca nut (which, by association, is often inaccurately called the "betel nut") and mineral slaked lime (calcium hydroxide). Catechu, called Kattha in Hindi, and other flavoring substances and spices might be added. The lime acts to keep the active ingredient in its freebase or alkaline form, thus enabling it to enter the bloodstream via sublingual absorption. The areca nut contains the alkaloid arecoline, which promotes salivation (the saliva is stained red), and is itself a stimulant. This combination, known as a "betel quid", has been used for several thousand years. Tobacco is sometimes added.

Betel leaves are used as a stimulant, an antiseptic and a breath-freshener. Betel quid is also strongly carcinogenic.