Sex Hormones: Not Just for Sex! - Part 1

Written by Anil Bajnath, MD
Posted October 27, 2020

Dear Reader,

Most people are familiar with the three basic sex hormones. Today, we'll talk about the first two: testosterone and estrogen. What’s less well-known is that these hormones do so much more than regulate sexual functions. They’re a vital part of keeping the body working properly, just like the rest of the hormones involved in the endocrine system.

Nothing in the body exists in a vacuum. Hormones are part of a complex system consisting of chemical signals, cellular receptors, glands, and organs. Researchers are still in the process of discovering the ins and outs of the endocrine system, and therefore it can be difficult for medical practitioners to diagnose and treat hormonal imbalances.

Thankfully, today there is a wide base of knowledge regarding hormones and testing you can do to get an idea of how yours are behaving. Men and women have very different requirements for their sex hormones and understanding the difference can be helpful to take proactive steps to better endocrine health.


Testosterone is the sex hormone most people relate to manliness- muscles, beards, deep voices, and testicles. And though it does have an effect on all these things, the truth is women have testosterone too (though in less abundance).

Testosterone is produced in the testes in men and the ovaries in women. All testosterone production is stimulated by the master pituitary gland and has a variety of functions including bone development, muscle growth, and body hair. It is testosterone that tells a boy’s body to become a man’s and keeps them feeling energetic and vital throughout life.

Like all hormones, the body requires a balance to operate efficiently. As men age, they experience a decline in testosterone that can happen gradually or quickly depending on a number of factors. Decreased testosterone in men can cause weight gain, decreased sexual desire, type 2 diabetes, thyroid imbalances, bone loss, muscle loss, and even cancer. That’s why it’s important to take note of testosterone levels as you age and make sure you’re living a lifestyle that promotes healthy production.

When a man is stressed (either from lifestyle factors, eating too few calories, or constant extreme cardio exercise), he produces the stress hormone, cortisol. Cortisol is known to decrease the amount of free testosterone in the body, meaning there is less that can be absorbed into cells to make things happen.

Measuring testosterone levels has been an ongoing challenge in medicine. Currently, blood serum is used to test hormone levels and is often used to diagnose endocrine disorders. It is known that in men, testosterone secretion follows a circadian rhythm, being highest in the morning and decreasing during the day. Therefore, it’s best to take samples for testing in the morning hours for the most accurate results.

Men, on average, have 7-8 times more testosterone than women. This makes testing for imbalances in women more challenging. There have also been varying measurements observed between laboratories, giving researchers a reason to begin looking for better methods of testing.


Estrogen is the “female hormone” but is also found in men. It’s produced mainly in the ovaries, but also in the adrenal glands and fat tissue.

Estrogen is not a single hormone, but a collective name we give to all three forms of it- estroneestradiol, and estriol. Together they help tissues grow (namely, the breasts, ovaries, and prostate) and help regulate serotonin in the brain.

Estrone (E1) is a weak estrogen. It is mostly produced by women that are post-menopausal. The effects of low estrone or high estrone levels are not currently well known but it is commonly associated with breast and prostate cancer. Because it’s produced in adipose (fat) tissue, women who are obese will produce more estrone and be put at risk for these cancers.

Estradiol (E2) is the primary estrogen produced in women during their child-bearing years. Its main duty is to mature the reproductive system and maintain it. It is the strongest of the estrogens and protects bone density, growth hormone levels, and mood in both men and women (though women have higher levels).

Having too much estradiol has been associated with acne, loss of sex drive, constipation, and depression. Extremely high levels can put women at risk for uterine and breast cancer. As a woman ages, her estradiol levels drop, resulting in the cessation of the menstrual cycle and the symptoms of menopause- hot flashes, mood swings, and vaginal dryness.

Estriol (E3) is the weakest form of estrogen and is responsible for protecting breast tissue and vaginal health. By occupying the receptors for estrone, it blocks its cancerous effects and maintains a healthy reproductive system.

In Part 2, we'll jump into the third sex hormone and a test you should take.

To your longevity,

Anil Bajnath, MD
CEO/Founder, Institute for Human Optimization
Chief Medical Advisor, Longevity Insider HQ

P.S. Speaking of tests, I have a few you can try now. Just take a look at them in my latest book, The Longevity Equation.

* This content is provided by the Institute for Human Optimization (