Ingredients of Birth Control

Birth control pills are one of the most common forms of birth control and are used to prevent the sperm from fertilizing the egg during intercourse. In addition to birth control pills, also called oral contraceptives, birth control patches and injections and emergency birth control are common forms of contraception that are hormone based. Over-the-counter birth control products do not rely on hormones to prevent pregnancy.

Estrogen

Oral contraceptives utilize synthetic female hormones to prevent an egg from being released from the ovary. Low-dose estrogen pills are available and contain 20 micrograms of estrogen compared to the usual amount of 30 to 50 micrograms. Most birth control pills contain both estrogen and progesterone (progestin) and are referred to as combination pills. Types of synthetic estrogen include ethinyl estradiol and mestranol. Hormone-based birth control can be delivered in pill form, through epidermal skin patches and long-lasting injections.

Progestin

Progestin is used in the making of birth control pills to create a hostile environment for sperm by changing the physical and chemical makeup of the reproductive tract. Progestin-only pills can prevent pregnancy for those women who cannot take estrogen or who are breast-feeding. Plan B is an emergency oral contraceptive used to prevent pregnancy when traditional methods like condoms fail, when regular birth control pills were skipped or when a woman had unprotected sex. Plan B pills contain the hormone levonorgestrel, which is a form of progestin in a dosage much higher than daily birth control pills, pharmacists at Walgreens report. Plan B contains no estrogen and is not meant to replace regular birth control pills.

Nonoxydol-9

The active birth control ingredient in spermicides is nonoxydol-9, a chemical that kills sperm, reports Dr. Donnica Moore, an author and women's health educator. Spermicides are sold over-the-counter in a variety of forms from gel and foam to cream and suppositories. Vaginal spermicides contain other ingredients that must be considered before using if either partner has chemical allergies. Most spermicides also contain trace amounts of benzalkonium chloride and octoxymol-0.