Topics Containing This Multimedia
		Contraception

Oral contraceptives contain progestin with or without estrogen, which prevents pregnancy by stopping ovulation (that is, the release of eggs by the ovaries). Oral contraceptive dispensers usually include a 28-day supply: 21 active tablets and 7 inactive tablets for use during the menstrual cycle.

(From KS Saladin, Anatomy and Physiology, 1998, WCB McGraw-Hill, p. 1020; with permission. © The McGraw-Hill Companies, Inc./Bob Coyle, photographer)