Hormonal Contraceptives

Many Types of Contraceptives

Although oral contraceptives were the first commercially available method of hormonal birth control, there are now many forms. The specific drugs used are the same, but may involve a novel delivery system such as an injection, skin patch, implant, or even a plastic ring placed inside the vagina. Mini-pills are like conventional oral contraceptives, but contain no estrogen.

Hormonal contraceptives are extremely popular due to their ease of use and efficacy. All require a doctor's prescription due to possible drug interactions and health risks, especially among older women and smokers. These methods of birth control can cause numerous side-effects and health risks — as well as some health benefits. Unwanted side-effects (below) can be entirely avoided if the other methods such as condoms, cervical barrier methods for women, or natural methods are used instead.

How Hormonal Methods Work

All hormonal contraceptives have at least three mechanisms of action. Artificial female hormones are the active ingredient in all hormonal contraceptives — estrogen and progestin. Some products contain both hormones and others progestin only. Using both hormones together is somewhat more effective than progestin alone, but the estrogen component is responsible for most of the serious health hazards associated with hormonal methods.

Hormonal contraceptives prevent ovulation. No egg is released so sperm cannot fertilize it. It is widely agreed that this is a major mechanism of hormonal birth control.

Hormonal contraceptives may also prevent fertilization by changing the consistency of natural secretions in the vagina, making it harder for the sperm to reach the egg. It is not clear how effective this mechanism is in preventing fertilization.

A woman may ovulate anyway, and sperm may still reach the egg, resulting in fertilization. When this occurs, hormonal contraceptives make it difficult for the embryo to implant in the uterus by keeping the edometrium (lining of the uterus) thinned. This results in the death and expulsion of the embryo. Most scientists agree this occurs, but it is not clear how often. Some doctors do not prescribe hormonal contraceptives because they find this mechanism objectionable. [more about this...]

Chemical Names

Types of Estrogens

  • ethynil estradiol
  • mestranol

Types of Progestins

  • desogestrel
  • drospirenone
  • ethynodiol diacetate
  • levonorgestrel
  • norethindrone
  • norgestimate
  • norgestrel
  • etonogestrel

Health Risks

There are numerous side-effects and health risks involving hormonal contraceptives. Hormonal contraceptives may increase your risk of breast cancer and cervical cancer, but reduce the risk of uterine or ovarian cancer; the science is not yet conclusive. Other side effects and health risks listed here, but not all are provided due to space limitations.

Problems caused by Estrogen component

  • Nausea
  • Breast swelling & tenderness
  • Vaginal discharge
  • High blood pressure
  • Decreased libido (sex drive)
  • Headaches
  • Mood swings
  • Fluid retention
  • Permanent dark patches on face
  • Drug interaction problems
  • Eye or vision problems
  • Gallbladder disease
  • Tumors of the liver
  • Breast cancer and/or tumor growth
  • Cervical cancer
  • Deep vein thrombosis (blood clot)
  • Pulmonary embolism (rare)
  • Heart attack (rare)
  • Stroke (rare)

Problems caused by Progestin component

  • Weight gain
  • Depression
  • Bone loss
  • Fatigue and tiredness
  • Acne and/or oily skin
  • Headaches
  • High blood pressure
  • High cholesterol
  • Insulin resistance
  • Constipation
  • Bloating
  • Irregular menstrual bleeding
  • Breast tenderness
  • Supression of immune system
  • Heart attack (rare)
  • Breast tumor growth (rare)

Hormonal Contraceptives and Cancer Risk

Hormone-based contraceptives are a multi-billion dollar industry, and most of the research supporting the safety and efficacy of these was funded by the companies that profit from their sale. Not surprisingly, side-effects and health risks are minimized by drug manufacturers. For example, according to the National Cancer Institute, oral contraceptives are linked to the development of breast and cervical cancers but protect against endometrial and ovarian cancers. Some oral contraceptives also help fight acne and PMS. Promotional literature for these products emphasizes the health benefits but minimizes breast cancer risk, even though breast cancer is much more common than other reproductive cancers (as shown in the table below) and much more serious than acne or PMS.

Lifetime Risk of Reproductive Cancers in All Women
Type of Cancer Risk of Contracting Risk of Dying Added Risk with
Hormonal Contraceptives

Uterine/ Endometrial

  • 1 in 8 (12%)
  • 1 in 142 (0.7%)
  • 1 in 71 (1.4%)
  • 1 in 41 (2.5%)
  • 1 in 34 (3%)
  • 1 in 434 (0.2%)
  • 1 in 91 (1.1%)
  • 1 in 190 (0.5%)
  • Increased
  • Increased
  • Decreased
  • Decreased

Hormonal Contraceptives and Failure Rates

Though fairly effective, actual failure rates of these methods are much higher when estimated based on nationwide surveys of actual women, rather than research studies with carefully selected couples. And, when something goes wrong, neither drug companies nor researchers are in a rush to publicize their failures. Even if investigators prepared reports describing failures, journal editors would probably not publish them.

Go to next section [oral contraceptives]

Related Articles

Extended Cycle Combined Oral Contraceptive Pills

Frequently Asked Questions about the Pill and Other Hormonal Methods

List of Contraceptives

Different Kinds of Contraceptives

Use of Contraceptives

Emergency Contraception Side Effects

How Does Emergency Contraception Work?


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