It’s no secret that sex hormones are instrumental to fertility and sexuality. The reproductive hormones are key players when it comes to puberty, pregnancy, sperm production, and libido. But these hormones can also influence brain function, body composition, metabolism, bone health, and much more. Given that sex hormones impact so many bodily functions, any imbalance can have wide-ranging effects – and can lead to a variety of unwanted symptoms across physical, mental, and emotional health.
Many people associate certain hormones with a specific sex: estrogen with females or testosterone with males, for example. But the truth is that those hormones, as well as the rest of the sex steroid hormones, exist in everyone, simply in different levels. And whether they’re produced in the testes or the ovaries (some are even produced in the adrenal glands!), each plays an essential role in sexual development and reproductive health.
Estrogen is a group of hormones that promote and maintain normal female sexual and reproductive development and health. Estrogen plays an important role in menstruation, pregnancy, menopause, and the development of female secondary sex characteristics, and is responsible for the growth of the uterine lining. It’s found in nearly every tissue of the body and affects the health of the urinary tract, heart, bones, brain, skin, hair, mucous membranes, and pelvic muscles.
There are three main forms of estrogen:
- Estradiol: the most potent form of estrogen, produced in the body during the reproductive years. This form of estrogen is also found in males and is essential for libido, erectile function, and sperm production.
- Estrone: the major form of estrogen in post-menopausal females
- Estriol: the major form of estrogen during pregnancy
Estrogen is normally formed in the ovaries, but during pregnancy it can be made by the placenta. The adrenals and fat tissue can also produce estrogen to a lesser degree. In males, estrogen is formed in the testes, brain, bones, skin, and fat tissue.
Progesterone is a hormone made by the corpus luteum in the ovaries and by the placenta during pregnancy. It’s also produced in the testes and can be produced in the adrenal glands.
Progesterone’s primary function is to stimulate the thickening of the uterine lining and prepare it for implantation of a fertilized egg. During pregnancy, high progesterone levels prevent ovulation and premature contractions and help prepare the breasts for lactation. Progesterone also plays an important role in mood, thyroid health, and keeping estrogen levels in balance. Progesterone is associated with sperm development in males as well.
Testosterone belongs to a group of hormones known as the androgens, which are present in both females and males but produced in higher levels in males. In fact, males have 20%–25% higher levels of testosterone than females do! In females, testosterone is produced in the ovaries and adrenal glands and plays a role in bone density, muscle mass, cardiovascular health, mood, cognition, and sexual function. In males, testosterone is produced in the Leydig cells of the testes and promotes the development of secondary sex characteristics (e.g., hair growth and voice deepening), regulates sex drive, and develops male reproductive tissues.
Dehydroepiandrosterone (DHEA) is an androgen produced by the ovaries or testes and from cholesterol in the adrenal cortex. It’s a precursor to both testosterone and estrogen. DHEA production peaks around the age of 25 and then begins to decline. This hormone is important for maintaining cognitive function, mood, and bone health. DHEA supplements are being investigated for many potential therapeutic applications, including poor libido, depression, adrenal insufficiency, menopausal relief, and inflammatory bowel disease.
Dihydrotestosterone (DHT) is an androgen made by testosterone in various body tissues with the help of an enzyme known as 5-alpha-reductase. It’s a key player in puberty, genital tissue development, and fetal development and supports healthy hair growth.
Androstenedione is an androgen produced by the ovaries or testes and the adrenal glands. It plays a key role in the production of estrogen and testosterone. It’s been marketed in supplement form with claims that it will boost testosterone levels and strength but has since been banned due to the risk of serious side effects, such as heart attack and stroke.