Understanding Your Sex Hormones
When it comes to your health, sex hormones do far more than regulate your period or sex drive. Estrogen, progesterone, and testosterone play major roles in everything from mood and metabolism to bone health and brain function. Understanding what these hormones do—and how they change over time—can help you tune into your body and recognize when something feels “off.”
Let’s break it down.
Estrogen: The Multi-Tasking Powerhouse
Estrogen is often labeled the “female hormone,” but both men and women have it—just in different amounts. Produced mainly in the ovaries (and in smaller amounts by the adrenal glands and fat cells), estrogen is responsible for:
Regulating the menstrual cycle
Supporting pregnancy and fertility
Building and maintaining bone density
Influencing mood, memory, and skin health
Supporting cardiovascular health
In women, estrogen begins rising in early puberty, prompting breast development, menstrual cycles, and body changes. It peaks in the reproductive years and then drops significantly during perimenopause and menopause, often contributing to hot flashes, vaginal dryness, mood shifts, and bone loss.
In men, estrogen is present at lower levels and helps regulate libido, sperm production, and bone health. Their levels decline gradually with age, usually starting around their 30s or 40s.
Progesterone: The Balancing Hormone
Progesterone is often called the “calming hormone.” It’s produced in the ovaries after ovulation and plays a crucial role in:
Regulating the menstrual cycle
Preparing the uterus for pregnancy
Supporting early stages of pregnancy
Helping promote better sleep and reduce anxiety
In women, progesterone levels start to rise with the onset of ovulation during puberty, peaking in the second half of the menstrual cycle (the luteal phase). If no pregnancy occurs, levels drop, triggering menstruation. During perimenopause and menopause, progesterone is often the first hormone to noticeably decline, which can lead to irregular cycles, anxiety, sleep disturbances, and heavy periods.
Men also produce small amounts of progesterone in the adrenal glands and testes, where it helps balance the effects of estrogen and supports sperm development.
Testosterone: The Energy and Drive Hormone
Testosterone is commonly viewed as the “male hormone,” but again, both sexes produce it. For women, it's made in the ovaries and adrenal glands. Testosterone is vital for:
Muscle mass and strength
Libido and sexual function
Motivation and energy
Mood stability
Bone density
In men, testosterone surges during puberty, causing voice changes, muscle growth, facial hair, and increased libido. It reaches its peak in the late teens to early 20s, then gradually declines about 1% per year starting around age 30. This slow drop can affect energy, mood, strength, and sexual function over time.
In women, testosterone also rises during puberty, contributing to libido and muscle tone. Levels naturally begin to drop in the late 20s to early 30s, with a more noticeable decline around menopause.
What Happens As We Age?
Women experience a more abrupt shift in hormone levels during perimenopause and menopause, often between ages 40–55. Estrogen and progesterone fall significantly, and testosterone declines more gradually.
Men experience a more gradual decline in testosterone and estrogen (yes, they have both!) over decades, often with subtler symptoms like decreased stamina, mood changes, or reduced libido.
Why This Matters
Changes in hormone levels can impact your energy, mood, weight, sleep, and overall health. Whether you're navigating puberty, perimenopause, menopause, or just trying to understand your body better, knowing what these hormones do is the first step to taking control of your well-being.
If you're feeling “off” and not sure why, it might be time to take a closer look at your hormones. At Arbor Internal Medicine, we offer personalized care and hormone evaluations to help you feel your best—at every stage of life.
Dr. Danielle Ivey
Internal Medicine | Women’s Health Advocate
Helping you understand your body and take back control of your health
