What is Stein-Leventhal syndrome?

Stein-Leventhal syndrome , also known as polycystic ovary syndrome (PCOS), is a hormonal disorder in women characterized by high levels of androgens and irregular or absent ovulation. It affects approximately 5% of women and is a common cause of female infertility. The syndrome can manifest around puberty with symptoms such as premature pubic hair growth, high insulin levels, and elevated androgen precursors. After puberty, symptoms may include irregular menstruation, infertility, and signs of excess androgens like acne and hirsutism. Treatment includes exercise, proper nutrition, and medications to suppress androgen production or induce ovulation.

What are the main symptoms of Stein-Leventhal syndrome?

Stein-Leventhal syndrome, also known as polycystic ovary syndrome (PCOS) , is a disorder characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation anovulation . Symptoms may include the premature development of pubic hair, elevated levels of molecules that can be converted to androgens, hyperinsulinemia, infrequent or absent menstrual cycles, infertility, hirsutism (excessive midline body hair), and acne. Some women may experience increased muscle mass, frontal balding, and a deepening of the voice. About 50% of affected women are obese, and as they age, menstrual irregularity and androgen excess become less of a problem, with symptoms often improving after age 40.

Who is most likely to develop Stein-Leventhal syndrome?

Stein-Leventhal syndrome, also known as polycystic ovary syndrome (PCOS), affects approximately 5% of women and is a common cause of female infertility. The syndrome is characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation. Insulin resistance appears to play a central role in the development of PCOS, with the ovaries being only one of several organs that may be affected. The syndrome may become apparent at or prior to puberty. After puberty, symptoms may include infrequent or absent menstrual cycles, infertility, and signs of excess levels of androgens, including hirsutism (excessive midline body hair) and acne.

How does Stein-Leventhal syndrome affect the female body?

Polycystic ovary syndrome (PCOS) , formerly known as Stein-Leventhal syndrome, affects roughly 5% of women and is a common cause of female infertility. It is characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation. Insulin resistance, where the body's tissues don't respond to insulin, appears to play a central role in the development of PCOS. The ovaries are only one of several organs that may be affected. The syndrome may become apparent at or before puberty. After puberty, symptoms may include infrequent or absent menstrual cycles, infertility, and signs of excess androgens, including excessive body hair and acne.

What causes Stein-Leventhal syndrome?

Polycystic ovary syndrome (PCOS), formerly known as Stein-Leventhal syndrome, is a condition characterized by high levels of male hormones (androgens) and irregular or absent ovulation. While the exact cause of PCOS is unknown, it is believed to be a complex disorder involving multiple physiological systems. Insulin resistance, where the body's tissues don't respond properly to insulin, seems to play a key role. This leads to increased insulin secretion, which can cause excess androgen production. PCOS symptoms can appear around puberty and include premature pubic hair growth, irregular menstrual cycles, infertility, excessive hair growth, and acne. Weight loss, exercise, and medication can help manage the condition.

Stein-Leventhal syndrome

Introduction References & Edit History Quick Facts & Related Topics

Images

Detailed cross-sectional illustration of a human ovary showing the stages of follicle development, ovulation, and corpus luteum formation, with labeled structures including primordial, primary, secondary, and mature follicles, a ruptured follicle releasing an ovum, and corpus luteum and albicans. An inset at the bottom shows the ovary's location in the female reproductive system.

Quick Facts

Also called:: polycystic ovary syndrome (PCOS)

Related Topics:: ovary

See all related content

Stein-Leventhal syndrome

medical disorder

Also known as: PCOS, polycystic ovary syndrome

Written by

Richard S. Legro

Fact-checked by

Britannica Editors

Last updated

Sep. 19, 2026 •History

Top Questions

What is Stein-Leventhal syndrome?
Stein-Leventhal syndrome, also known as polycystic ovary syndrome (PCOS), is a hormonal disorder in women characterized by high levels of androgens and irregular or absent ovulation. It affects approximately 5% of women and is a common cause of female infertility. The syndrome can manifest around puberty with symptoms such as premature pubic hair growth, high insulin levels, and elevated androgen precursors. After puberty, symptoms may include irregular menstruation, infertility, and signs of excess androgens like acne and hirsutism. Treatment includes exercise, proper nutrition, and medications to suppress androgen production or induce ovulation.
1 Britannica Source
1. Stein-Leventhal syndrome
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are the main symptoms of Stein-Leventhal syndrome?
Stein-Leventhal syndrome, also known as polycystic ovary syndrome (PCOS), is a disorder characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation anovulation.

Symptoms may include the premature development of pubic hair, elevated levels of molecules that can be converted to androgens, hyperinsulinemia, infrequent or absent menstrual cycles, infertility, hirsutism (excessive midline body hair), and acne. Some women may experience increased muscle mass, frontal balding, and a deepening of the voice. About 50% of affected women are obese, and as they age, menstrual irregularity and androgen excess become less of a problem, with symptoms often improving after age 40.
2 Britannica Sources
1. Stein-Leventhal syndrome
2. androgen: Androgen excess in women
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Who is most likely to develop Stein-Leventhal syndrome?
Stein-Leventhal syndrome, also known as polycystic ovary syndrome (PCOS), affects approximately 5% of women and is a common cause of female infertility. The syndrome is characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation. Insulin resistance appears to play a central role in the development of PCOS, with the ovaries being only one of several organs that may be affected. The syndrome may become apparent at or prior to puberty. After puberty, symptoms may include infrequent or absent menstrual cycles, infertility, and signs of excess levels of androgens, including hirsutism (excessive midline body hair) and acne.
1 Britannica Source
1. Stein-Leventhal syndrome
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does Stein-Leventhal syndrome affect the female body?
Polycystic ovary syndrome (PCOS), formerly known as Stein-Leventhal syndrome, affects roughly 5% of women and is a common cause of female infertility. It is characterized by elevated levels of male hormones (androgens) and infrequent or absent ovulation.

Insulin resistance, where the body's tissues don't respond to insulin, appears to play a central role in the development of PCOS. The ovaries are only one of several organs that may be affected. The syndrome may become apparent at or before puberty. After puberty, symptoms may include infrequent or absent menstrual cycles, infertility, and signs of excess androgens, including excessive body hair and acne.
1 Britannica Source
1. Stein-Leventhal syndrome
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What causes Stein-Leventhal syndrome?
Polycystic ovary syndrome (PCOS), formerly known as Stein-Leventhal syndrome, is a condition characterized by high levels of male hormones (androgens) and irregular or absent ovulation. While the exact cause of PCOS is unknown, it is believed to be a complex disorder involving multiple physiological systems.

Insulin resistance, where the body's tissues don't respond properly to insulin, seems to play a key role. This leads to increased insulin secretion, which can cause excess androgen production. PCOS symptoms can appear around puberty and include premature pubic hair growth, irregular menstrual cycles, infertility, excessive hair growth, and acne. Weight loss, exercise, and medication can help manage the condition.
1 Britannica Source
1. Stein-Leventhal syndrome
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How is Stein-Leventhal syndrome diagnosed and treated?
Stein-Leventhal syndrome, also known as polycystic ovary syndrome, is diagnosed based on elevated androgen levels and infrequent or absent ovulation, not necessarily the presence of ovarian cysts.

Treatment begins with exercise and proper nutrition to encourage weight loss and improve insulin sensitivity. If these are not successful, or if the syndrome is severe, treatment is focused on suppressing excess androgen production. Oral contraceptives or anti-androgen drugs can manage hirsutism and menstrual irregularities in women who do not want to become pregnant. Drugs that induce ovulation, like clomiphene citrate or gonadotropins, can treat infertility in women who wish to become pregnant. In some cases, antidiabetic drugs can increase ovulatory frequency and decrease excess androgen levels.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Stein-Leventhal syndrome, disorder in women that is characterized by an elevated level of male hormones (androgens) and infrequent or absent ovulation (anovulation). About 5 percent of women are affected by Stein-Leventhal syndrome, which is responsible for a substantial proportion of cases of female infertility. The syndrome was first described in 1935 when American gynecologists Irving F. Stein, Sr., and Michael L. Leventhal associated the presence of ovarian cysts with anovulation. For many years these factors were used as the diagnostic criteria of the syndrome. Later, it was realized that anovulation and an elevated level of androgens, not ovarian cysts, were the more correct diagnostic criteria, since it is the combination of these factors that results from or is symptomatic of the other characteristics of the syndrome. While the cause of the syndrome remains unknown, evidence suggests that the syndrome is complex, involving multiple physiological systems. For example, insulin resistance appears to play a central role in the development of the disease, with the ovaries being only one of several organs that may be affected.

Insulin resistance occurs when certain tissues, primarily skeletal muscles, do not respond to insulin. This results in a compensatory increase in the secretion of insulin by the pancreas, causing an increase in the serum concentrations of insulin (hyperinsulinemia). Hyperinsulinemia can lead to the excess production of androgens through a number of pathways, including stimulation of the hypothalamus, stimulation of the adrenal glands and the ovaries, and suppression of the circulating levels of sex-hormone-binding globulin, which allows androgens to readily leave the circulation and enter tissues (e.g., hair follicles) where they exert their actions. Insulin resistance and compensatory hyperinsulinemia are also risk factors for other metabolic diseases, including type II diabetes and atherosclerosis, which women with Stein-Leventhal syndrome may develop at an unusually young age. In addition, obesity is present in about 50 percent of affected women and is often associated with the presence of other metabolic problems. Hyperinsulinemia, obesity, and chronic anovulation may also lead to the development of endometrial cancer (uterine cancer).

The syndrome may become apparent at or prior to puberty, at which time symptoms may include premature development of pubic hair, hyperinsulinemia, and elevated levels of precursor molecules that can be converted to androgens. After puberty, symptoms may include infrequent or absent menstrual cycles, infertility, and signs of excess levels of androgens, including hirsutism (excessive midline body hair) and acne. As affected women grow older, menstrual irregularity and androgen excess become less of a problem, with these symptoms often improving after the age of 40. In fact, diagnosis of the syndrome is difficult to make after the onset of menopause. Because affected women exhibit a wide variety of signs and symptoms, some authorities believe that the syndrome is not one but several different syndromes. In addition, no genetic cause has been identified, although the syndrome sometimes appears in multiple women in one family.

Britannica Quiz

44 Questions from Britannica’s Most Popular Health and Medicine Quizzes

The most basic form of treatment of women with Stein-Leventhal syndrome is the initiation of an exercise regimen combined with proper nutrition to encourage weight loss and to improve insulin sensitivity. If these measures are unsuccessful, or if the syndrome is severe, treatment is focused on suppressing excess androgen production. In women who do not wish to become pregnant, hirsutism and menstrual irregularities can be managed with oral contraceptives or anti-androgen drugs. In women who do wish to become pregnant, infertility is often treated with drugs that induce ovulation, such as clomiphene citrate or gonadotropins. Less commonly, laparoscopic surgery is used to destroy portions of the ovary and thus reduce the production of androgens. In addition, antidiabetic drugs have been used in some patients to increase ovulatory frequency and to decrease excess androgen levels.

Richard S. Legro

Stein-Leventhal syndrome

Thank you for signing up!