Understanding PCOS Hormone Levels

Polycystic ovary syndrome, or polycystic ovarian syndrome, is a common endocrine disorder affecting people assigned female at birth. 

PCOS is characterized by multiple cysts on the ovaries, irregular menstrual periods, difficulty falling pregnant, and high levels of androgens (male hormones) in the body. 

PCOS can involve significant changes in hormone levels, and understanding them can help you learn more about your condition, advocate for yourself, and deal with bothersome symptoms and side effects.

What is PCOS?

PCOS is a syndrome of an unclear cause that can often go underdiagnosed. It is a result of hormonal imbalances, including hyperandrogenism (excessive amounts of male hormones such as testosterone).

While it primarily affects the reproductive system, it is a systemic disease that can, among other things, increase the risk of type 2 diabetes and heart disease. 

What are the symptoms of PCOS?

PCOS symptoms can vary wildly between individuals. However, the classic symptoms include:¹

• Irregular or absent menstruation

• Excessive hair growth of a typically male pattern, including facial hair (hirsutism)

• Male pattern baldness

• Weight gain

• Oily skin

• Acne that persists into, or begins in, adulthood

• Difficulty falling pregnant

Many people with PCOS only discover the problem when they attempt to get pregnant, while others may have stronger symptoms and be diagnosed in adolescence.

Diagnosing PCOS using hormone levels

PCOS is typically diagnosed based on a combination of signs and symptoms, as well as a hormone test and imaging results. There is no definitive test to diagnose PCOS.

Hormone levels and PCOS

The following reproductive hormones appear to be impacted by PCOS.

Luteinizing hormone (LH)

Luteinizing hormone is produced by the pituitary gland and plays a key role in normal sexual function. It triggers the release of eggs from the ovaries and induces the production of estrogen and progesterone from the ovaries.²

It is sometimes used to track ovulation, as the spike in the hormone right beforehand is obvious. It can also be used to confirm that you have reached menopause.

In people with PCOS, levels of LH tend to be higher than normal, although this does not appear to trigger ovulation. Instead, it may be connected to the elevated levels of testosterone found in PCOS patients.

Follicle-stimulating hormone (FSH)

Follicle-stimulating hormone stimulates the growth of an egg within the ovary. FSH is vital for the production of healthy eggs. Both FSH and LH are typically tested at the same time.³

In people with PCOS, levels of FSH are normal or lower than normal, and there is an imbalance in the ratio of LH and FSH, with LH higher compared to FSH. 

Total and free testosterone

There are two types of testosterone: total testosterone and free testosterone. Total testosterone is the total amount of testosterone in the blood and includes both bound and unbound testosterone. Free testosterone is the amount of testosterone that is not bound to a protein and is therefore available to enter cells and exert its effects. 

In PCOS, the levels of both total testosterone and free testosterone may be elevated, and the levels of total testosterone are usually measured to evaluate the level of androgens in the blood. Some people with PCOS still have normal testosterone levels, and if you’re on oral contraception, your testosterone levels will be lower.

Sometimes, sex hormone-binding globulin (SHBG) is measured as an indirect way of measuring testosterone. SHBG binds and transports sex hormones such as testosterone and estrogen in the bloodstream, making them less available to target cells. High levels of testosterone seen in PCOS, thus, may result in low levels of SHBG. 

Dehydroepiandrosterone sulfate (DHEAS)

DHEA sulfate is a byproduct of testosterone and is often used as a marker of androgen excess in the body. DHEAS is produced by the adrenal glands and its levels can be raised in PCOS. High levels of DHEAS can cause masculinization in AFAB individuals.⁴

Prolactin

Prolactin is the hormone that signals the breasts to produce milk after pregnancy. Elevated prolactin can cause lactation in women who are not pregnant or breastfeeding and the same in men. It affects fertility and sexual function.⁵

Prolactin is usually normally or mildly raised in PCOS. Levels are not high enough to induce lactation. Significantly elevated prolactin is associated with prolactinoma, a kind of tumor of the pituitary gland that is typically benign. 

Prolactin is tested in the investigation for PCOS to ensure menstrual irregularities are not caused by an adrenal condition such as a prolactinoma. 

Androstenedione

Androstenedione is a natural steroidal hormone produced in the adrenal glands and ovaries and plays a role in producing both estrogen and testosterone. It is sometimes used by athletes to increase testosterone levels. But it is not scientifically proven, and it is a banned performance-enhancing drug in most athletic organizations.⁶

Androstenedione levels are significantly elevated in individuals with PCOS over normal females. The role of androstenedione in PCOS is not fully understood, and more research is needed to determine its exact role in the condition.

Progesterone

Progesterone is also a steroidal hormone. It is produced by the ovaries regularly during the normal menstruation cycle after ovulation to prepare the lining of the womb for pregnancy. The ovaries produce the hormone in the first ten weeks of pregnancy, and then the placenta produces it. It is considered the hormone of pregnancy.⁷

Progesterone is significantly reduced in individuals with PCOS, and supplementing it is part of the treatment for infertility in individuals with PCOS who want to get pregnant.

Other hormones

A thyroid stimulating hormone test may also be conducted to ensure that menstrual irregularities are not being caused by a thyroid condition. A fasting glucose and fasting insulin hormone levels test may also be conducted to test for insulin resistance, which is often associated with PCOS. 

The lowdown

If you have PCOS, then you may have abnormal levels of a wide variety of reproductive hormones. Some may be too high, such as LH, testosterone, DHEAS, androstenedione, and prolactin. Others, such as FSH and progesterone, are too low. These abnormal levels can lead to the symptoms of PCOS and have a significant negative impact on your fertility.

As PCOS is so poorly understood, it is important to advocate for yourself and ask for extra tests if you think they will help get to the bottom of your condition, especially if you are contemplating pregnancy.