Premarin tablets contain conjugated estrogens, a mixture of estrogens obtained from natural sources. Estrogen is a female sex hormone produced by the ovaries. Estrogen is necessary for many processes in the body. Premarin is used to treat symptoms of menopause such as hot flashes, and vaginal dryness, burning, and irritation. Other uses include prevention of osteoporosis in postmenopausal women, and replacement of estrogen in women with ovarian failure or other conditions that cause a lack of natural estrogen in the body.