Medical Health Encyclopedia

Birth Control Options for Women - Oral Contraception

(Page 2)




Progestins may be used alone or with estrogen in oral contraceptives. In addition, certain specific progestins are used in other kinds of contraceptives, such as etonogestrel in the Implanon implant and depo-medroxyprogesterone acetate in the injectable contraceptive Depo-Provera.

Progesterone can prevent pregnancy by itself in several ways:

  • Blocking luteinizing hormone (LH) and preventing ovulation
  • Maintaining a powerful barrier against the entry of sperm into the uterus by keeping the cervical mucus thick and sticky

Progestins used in contraceptives are referred to as:

  • Second generation (levonorgestrel, norethisterone)
  • Third generation (desogestrel, gestodene, norgestimate, drospirenone). The third-generation progestins tend to have fewer side effects. Some studies suggest, however, they may pose a slightly higher risk for blood clots than the older progestins.



Combination Estrogen-Progestin Contraceptive Pills

Oral contraceptives that contain both estrogen and progestin are the more common type of oral contraceptive. At least 10 million American women and 100 million women worldwide use combination oral contraceptives. When they were first marketed in the early 1960s, oral contraceptives contained as much as 5 times the amount of estrogen and up to 10 times the amount of progestin currently used. After reports of severe complications (stroke, heart attack, and pulmonary embolisms) in young women, the hormone amounts were significantly reduced.

The estrogen compound used in most oral contraceptives is ethinyl estradiol (also called estradiol, or EE). Fifty micrograms of estradiol is considered high dose, 30 - 35 micrograms are considered average dose, and 20 micrograms or fewer is low-dose. (The high doses found in current oral contraceptives are still much lower than earlier forms of the pill.) Doctors recommend using the lowest possible progestin and estrogen doses. Estrogen doses should not exceed 50 micrograms, as higher doses increase the risk for complications.

Many different types of progestins are used in combination with estradiol. Some common types of progestin, and popular combination oral contraceptive brands, include:

Find a Therapist
PR Newswire