Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common hormonal disorder among women of reproductive age and is a leading cause of infertility. The disorder often goes undiagnosed because of its many, seemingly unrelated symptoms. Read more about PCOS and its treatment on the Hormone Health Network’s web section and in related fact sheets.


Polycystic Ovary Syndrome (PCOS) is defined by the presence of irregular menstrual cycles, excess body and/or facial hair, and polycystic ovaries, although not all women with the disorder have all these features. The term “polycystic” means “many cysts,” and PCOS gets its name because of the clusters of small, pearl-size cysts in the ovaries. These cysts are fluid-filled bubbles (called follicles) containing eggs that are immature.

While the ovaries and adrenal glands of all women release small amounts of “male hormones” called androgens, women with PCOS produce slightly higher amounts. Androgens play a role in helping women grow and develop strong bones and muscles, and in sexual function. However, higher androgen levels can interfere with ovulation and normal egg development. Instead of an egg maturing and being released as usual each month, the follicles containing the eggs build up in the ovaries. This results in infrequent ovulation so that most women with PCOS have irregular and infrequent menstrual periods.

The large number of small fluid -filled follicles in the ovaries leads to their polycystic appearance and their often enlarged size. However, there is a difference between large cysts (generally bigger than 1 inch) some women develop and which may need more careful medical attention, and the small cysts of polycystic ovary syndrome.

The cause of PCOS remains unknown. Research suggests that many women with this condition may have decreased sensitivity to insulin, called insulin resistance. Insulin, a hormone produced by the pancreas, is necessary to carry sugar from the bloodstream into the cells, where it is used for energy. When cells are resistant to the effects of insulin, the pancreas produces more insulin than normal to get cells to absorb enough sugar. This leads to high insulin levels in the bloodstream which, among other effects, make the ovaries overproduce male hormones. This creates a hormone imbalance that triggers or worsens some of the symptoms of PCOS. Insulin resistance also increases the risk of developing diabetes.

PCOS seems to run in families. Sisters of women with polycystic ovary syndrome have about a 50 percent chance of also having PCOS.

While there is still no cure for PCOS, the good news is that there are many effective ways to treat this condition. Together with changes in diet and exercise, these treatments are helping women with PCOS lead healthier and more satisfying lives. Even the problem of infertility can often be corrected.

PCOS Symptoms

PCOS is a syndrome, meaning that it is a collection of signs (physical findings) and symptoms (what the patient feels), so each person may have a different combination of features than another person. If you have two or more of the following symptoms, you should see your doctor for an accurate diagnosis and a treatment for PCOS that is right for you.

  • Irregular or absent menstrual periods. Nine or fewer periods per year may be a clue that a woman has PCOS. Bleeding may be heavier than normal.
  • Infertility. Women with polycystic ovary syndrome do not ovulate regularly so they may have trouble getting pregnant.
  • Excess or unwanted body or facial hair growth. PCOS may cause usually fine hairs on a woman's face to become heavier and darker. There may also be increased hair growth on a woman's arms, legs, and elsewhere on her body.
  • Thinning hair on the scalp.
  • Weight problems. Many women with polycystic ovary syndrome gain weight easily and have trouble losing extra pounds. Weight gain often is concentrated around the waist. Weight gain is of concern because it puts women at risk for health problems such as type 2 diabetes and heart disease.
  • Skin problems.
    • Acne on the face, chest, and back.
    • Skin tags, about the size of small raisins, in the armpits or neck.
    • Darkening and thickening of the skin around the neck, groin, underarms, or skin folds.

Complications of PCOS

Women with polycystic ovary syndrome are at higher risk for a number of serious health conditions. These conditions may go unnoticed, but are potentially dangerous.

  • Diabetes, elevated insulin levels, or insulin resistance. Most women with PCOS have problems using their body's insulin, the hormone that carries sugar from the bloodstream into our cells. About 30 percent of women with PCOS will have some problem processing blood sugar. This is a major risk factor for diabetes, a disease in which there is too much sugar in the bloodstream.
  • Heart and blood vessel diseases including high blood pressure. Women with PCOS often have high levels of bad cholesterol (LDL), low levels of good cholesterol (HDL), and high levels of other fats, including triglycerides. These factors are known to increase the risk of heart attack or stroke later in life.
  • Cancer of the uterus. The lining of the uterus—called the endometrium—normally builds up and is shed during the menstrual period each month. Because of irregular menstrual cycles and lack of ovulation in women with PCOS, the endometrium may not shed as often and may become extremely thick. If PCOS goes untreated, and the lining of the uterus does not shed as it should, this may increase the risk of cancer over time.
  • Sleep apnea. Sleep apnea—brief interruptions of breathing during sleep—is among the most common cause of all sleep disorders, but most people do not know they have it. These breathing irregularities cause snoring and fragmented sleep that result in daytime drowsiness. Untreated, the problem can be life threatening, increasing the risk for stroke, heart disease, and heart attacks.

Treatment Options for PCOS

Once you are correctly diagnosed, you can begin any of a number of treatments for polycystic ovary syndrome depending on the specific symptoms you are having, your age, and your plans for pregnancy. Some treatments can relieve distinct symptoms such as acne and weight gain, for example. Other treatments can help to put your body back into balance with the proper amounts of hormones.

  • Birth control pills, or oral contraceptives, contain female hormones that help regulate menstrual cycles. Contraceptives also help to lower levels of androgens, reducing abnormal hair growth and improving acne. They also prevent the potential build-up of the lining of the uterus, which can increase the risk of uterine cancer.
  • Insulin-sensitizing medications used to treat type 2 diabetes are useful for many women with PCOS. Although these medications have not been approved by the U.S. Food and Drug Administration (FDA) specifically for the treatment of PCOS, they seem to help menstrual cycles become more regular by lowering insulin levels and potentially helping women with insulin resistance to lose weight. Metformin is the most commonly used drug. You should have a conversation with your doctor before starting this medication. There is not enough research at this time to recommend this drug for all women with PCOS.
  • Ovulation induction to allow the release of an egg may be needed in women who want to get pregnant. Several treatment options are available to induce ovulation.
    • Clomiphene citrate, an oral medication taken for five days, is usually the initial treatment.
    • Gonadotropins are hormones that the body produces to stimulate ovulation. If clomiphene is not effective, the next step often includes an injection of gonadotropins.
    • Metformin may help induce ovulation in some women with PCOS, but it is generally less effective than clomiphene or gonadotropins. .
    • Weight loss itself can lead to a return of regular menstrual cycles in many women with PCOS. Typically, a loss of 5 to 10 percent of body weight is needed to have this effect.
    • High-tech treatments include in vitro fertilization, in which eggs are extracted from the ovary, fertilized with sperm in a laboratory; then the embryo(s) implanted in the uterus. This can lead to pregnancy even if it ovulation cannot be induced through other treatment options.
  • Androgen-blocking (anti-androgen) medications can be used to treat several PCOS symptoms, including excess or unwanted hair growth and, to a limited degree, acne and scalp hair loss. Anti-androgens include spironolactone, flutamide, finasteride, and cyproterone acetate (which is not available in the United States). These medications can be taken along with oral contraceptives. Although they have been used extensive worldwide to treat PCOS, none of these medications have been FDA-approved specifically for PCOS treatment. Anti-androgen medications can cause birth defects, so women who are pregnant or trying to get pregnant should not take them.
  • Topical anti-hair-growth medications containing eflornithine hydrochloride also can help to slow the growth of facial hair in women with PCOS. The active ingredient in this medication blocks an enzyme in the hair follicle of the skin needed for hair growth. This results in slower hair growth within a few weeks of treatment. This medication is FDA-approved for use on the face only.
  • Other treatments for excess hair caused by PCOS include bleaching, depilatory creams, and shaving excess hair. These treatments are safe and easy approaches. Electrolysis and laser treatments to remove hair also can work well. Waxing and tweezing, particularly of sensitive skin areas, can damage the skin, however, and are discouraged.
  • Treatments for hair loss tend not to work for everyone. Some women find improvements with the use of anti-androgen pills. Others find that minoxidil—a topical medication—can help as well.
  • Acne treatments sold over the counter also can help control the skin blemishes related to PCOS. Some women with severe acne may need prescription medicines such as isotretinoin. Many women also find that birth control pills improve their acne.
  • Skin problems other than acne may be treated in different ways. You can ask your doctor or dermatologist to remove skin tags using just a simple anesthetic on your skin. The dark blemishes on your skin may fade if you can reduce your insulin levels. Other treatments include tretinoin gel, 15 percent urea, alpha hydroxy acid, and salicylic acid.

Lifestyle and Prevention

You can take steps to stay as healthy as possible.

Proper nutrition is an important part of treatment for PCOS. Follow a healthy diet by eating fewer refined carbohydrates—white flour foods such as cereals, breads, and pastas—and replacing them with complex carbohydrates. Complex carbohydrates, including whole grains, fruits, and vegetables, can help reduce spikes in blood sugar after you eat. Your diet should also include enough protein to control the amount of sugar in your blood.

Exercise helps the body use insulin more effectively. It helps with weight loss and keeping off weight. Many studies have shown that exercising for at least 30 minutes a day, about five days a week, has many health benefits.

Weight loss can help with insulin resistance, reduce the male hormone levels, and help some women ovulate naturally.

Monitoring your health also is important if you have PCOS. You should have your blood sugar level, cholesterol levels, and blood pressure checked regularly to help reduce the risk of developing diabetes and cardiovascular disease.

With proper diagnosis, treatment, and lifestyle changes, most PCOS symptoms can be reversed or at least managed and your risk of developing health problems greatly reduced.


Cristina Meriggiola, MD, PhD
University of Bologna

Musa Zamah, MD, PhD
University of California, San Francisco

Last Review: May 2013