Topics Containing This Multimedia
		Contraception

Injection of medroxyprogesterone, a progestin, prevents pregnancy by stopping the menstrual cycle. Injections into the buttocks or upper arms once every 3 months may be effective for 3 months to 1 year.

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