The Medical Benefits Of Progesterone

Progestins are hormones. They are used by both men and women for different purposes.

Progesterone is a hormone produced mainly by the ovaries and the placenta in female animals during the period when they are able to bear young. This hormone can also be produced by the adrenal glands in both the females and males by the testes in males. It plays an important role in the normal menstrual cycle and in pregnancy. When the egg leaves its follicle in the ovary, the follicle is transformed into the corpus luteum. The corpus luteum manufactures progesterone, apparently from cholesterol. Progesterone then acts upon the uterine lining, which has already been primed by the female sex hormone, estrogen, in preparation for the egg. If the egg is not fertilized, progesterone production ceases, menstruation occurs, and the corpus luteum degenerates; if the egg is fertilized, the corpus luteum continues to secrete progesterone. This maintains pregnancy, prevents egg from maturing in ovary, inhibits menstruation, and stimulates growth of the breasts. Later in pregnancy progesterone manufacture is taken over by placenta, the structure through which the developing fetus receives nutrition.

Progestins are prescribed for several reasons:

  • To properly regulate the menstrual cycle and treat unusual stopping of the menstrual periods (amenorrhea). Progestins work by causing changes in the uterus. After the amount of progestins in the blood drops, the lining of the uterus begins to come off and vaginal bleeding occurs (menstrual period). Progestins help other hormones start and stop the menstrual cycle.
  • To help a pregnancy occur during egg donor or infertility procedures in women who do not produce enough progesterone. Also, progesterone is given to help maintain a pregnancy when not enough of it is made by the body.
  • To prevent estrogen from thickening the lining of the uterus (endometrial hyperplasia) in women around menopause who are being treated with estrogen for ovarian hormone therapy (OHT). OHT is also called hormone replacement therapy (HRT) and estrogen replacement therapy (ERT).
  • To treat a condition called endometriosis or unusual and heavy bleeding of the uterus (dysfunctional uterine bleeding) by starting or stopping the menstrual cycle.
  • To help treat cancer of the breast, kidney, or uterus. Progestins help change the cancer cell's ability to react to other hormones and proteins that cause tumor growth. In this way, progestins can stop the growth of a tumor. Progesterone is the hormone most often used to treat kidney cancer.
  • To test the body's production of certain hormones such as estrogen.
  • To treat loss of appetite and severe weight or muscle loss in patients with acquired immunodeficiency syndrome (AIDS) or cancer by causing certain proteins to be produced that cause increased appetite and weight gain.

Progestins may also be used for other conditions as determined by your doctor.

Depending on how much and which progestin you use or take, a progestin can have different effects. For instance, high doses of progesterone are necessary for some women to continue a pregnancy while other progestins in low doses can prevent a pregnancy from occurring. Other effects include causing weight gain, increasing body temperature, developing the milk-producing glands for breast-feeding, and relaxing the uterus to maintain a pregnancy.

Progestins can help other hormones work properly. Progestins may help to prevent anemia (low iron in blood), too much menstrual blood loss, and cancer of the uterus.

Doctors use progesterone as a drug to treat disorders of the reproductive system, such as premenstrual tension, infertility, and miscarriage. Synthetic forms of progesterone are used alone and in combination with synthetic estrogen in birth control pills.

All women who lack the female hormone estrogen are at increased risk of developing osteoporosis, a weakening of bones that makes them break with the slightest trauma. Previously, doctors routinely prescribed estrogen to prevent osteoporosis, but several recent reports show that the anti-estrogen, tamoxifen, and a second female hormone, progesterone, each help to prevent osteoporosis.

A woman is supposed to menstruate every 25 to 35 days. If she does not, she should be checked by her doctor and probably will be given hormone replacement. A woman is supposed to have two hormones, estrogen and progesterone. If she lacks progesterone, she is at increased risk of developing uterine cancer. If she lacks both estrogen and progesterone, she is at increased risk of developing osteoporosis.

Food manufacturers who claim that their products are "natural" are just playing with words, but recent research shows that natural progesterone may be far more healthful than a synthetic cousin that is prescribed to most postmenopausal women.

The vast majority of physicians recommend the female hormone, estrogen, for their postmenopausal patients because it helps to prevent hot flushes, osteoporosis, heart attacks, strokes, vaginal dryness, loss of IQ, depression, loss of teeth and Alzheimer's disease, but, giving estrogen increases a woman's chances of suffering uterine cancer sixfold. If she takes a second female hormone, progesterone along with estrogen, she is not at increased risk for getting uterine cancer.

Estrogen replacement therapy in postmenopausal women is known to improve the lipid profile-increasing HDL cholesterol, reducing LDL cholesterol-thus reducing the risk of heart disease. But what is the effect of progesterone on lipid levels and the risk of heart disease or cancer? According to medical investigators at the University of Maryland and University of California, San Diego, estrogen plus progesterone has a beneficial effect on the heart, and natural progesterone may offer a better benefit/risk ratio than synthetic progesterone.

The investigators reported the results from the $22 million Postmenopausal Estrogen/Progesterone (PEPI) trial begun by the National Institutes of Health in 1987. The 3-year placebo-controlled PEPI trial involved 875 healthy postmenopausal women (aged 45 to 64 years) who were given either estrogen alone, estrogen with synthetic progesterone (two different formulations) or estrogen combined with a plant- derived micronized progesterone. This is the first large-scale human trial of the natural progesterone, which has the same structure as human progesterone.

Compared with the placebo group, all subjects in the active treatment groups showed a significant elevation in HDL cholesterol. However, effects on HDL cholesterol were better in the natural progesterone group than in the synthetic progesterone groups. Estrogen alone increased HDL by 6 mg/dL, and estrogen/synthetic progesterone increased HDL by 2 mg/dL, with estrogen/natural progesterone falling in between. Women with the greatest rise in HDL reduced their risk of heart disease by 25%, said the investigators. Both active and placebo groups showed a reduction in LDL cholesterol, but the placebo group showed a much smaller rise.

Known Hazards: For oral or vaginal progesterone, dizziness or drowsiness may occur 1 to 4 hours after taking or using it. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Unusual or unexpected vaginal bleeding of various amounts may occur between your regular menstrual periods during the first 3 months of use. This is sometimes called spotting when slight, or breakthrough menstrual bleeding when heavier. If this should occur, continue on your regular dosing schedule. Check with your doctor :

If unusual or unexpected vaginal bleeding continues for an unusually long time. If your menstrual period has not started within 45 days of your last period.

Missed menstrual periods may occur. If you suspect a pregnancy, you should stop taking this medicine immediately and call your doctor . Your doctor will let you know if you should continue taking the progestin.

In some patients, tenderness, swelling, or bleeding of the gums may occur. Brushing and flossing your teeth carefully and regularly and massaging your gums may help prevent this. See your dentist regularly to have your teeth cleaned. Check with your medical doctor or dentist if you have any questions about how to take care of your teeth and gums, or if you notice any tenderness, swelling, or bleeding of your gums.

You will need to use a birth control method while taking progestins for noncontraceptive use if you are fertile and sexually active .

If you are using vaginal progesterone, avoid using other vaginal products for 6 hours before and for 6 hours after inserting the vaginal dose of progesterone.

  • MedlinePlus. U.S. National Library of Medicine. Progestins for Noncontraceptive Use
  • What You Need To Know About? Cancer. Kidney Cancer. The National Cancer Institute (NCI)
  • Dr. Gabe Mirkin. PROGESTERONE TO PREVENT OSTEOPOROSIS. Report #6305 8/8/94 and NATURAL PROGESTERONE Report #7059; 3/13/97

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