Yes, everyone has estrogen. It is not exclusively a “female hormone.” Every human body produces estrogen and relies on it for functions that go well beyond reproduction, including bone strength, brain health, and cardiovascular protection. The difference between males and females is one of quantity, not presence or absence.
How Estrogen Works in All Bodies
Estrogen acts on the neuroendocrine, vascular, skeletal, and immune systems in both males and females. It helps regulate cholesterol and triglyceride metabolism, protects neurons from oxidative damage, and plays a direct role in maintaining bone density. These aren’t secondary or minor effects. In men with genetic mutations that prevent their bodies from producing or responding to estrogen, the consequences are severe, including refractory osteoporosis and disrupted bone development.
Both male and female bodies also carry estrogen receptors in the brain. These receptors are involved in mood regulation, motor coordination, pain sensitivity, cognition, and protection against neurodegenerative conditions like Alzheimer’s and Parkinson’s disease. Studies comparing receptor distribution between males and females have generally found no significant differences.
Where Estrogen Comes From in Males
In females, the ovaries are the primary source of estrogen during reproductive years. But males produce estrogen too, through multiple pathways. The testes are a significant source: specialized cells called Leydig cells and germ cells both actively synthesize estrogen, creating relatively high concentrations within the reproductive tract. The brain also produces estrogen in meaningful quantities.
The key mechanism is an enzyme called aromatase, which converts testosterone into estradiol (the most potent form of estrogen). This conversion happens not only in the testes and brain but also in fat tissue, bone, and blood vessel walls. So even outside the reproductive organs, the male body is continuously generating estrogen from circulating testosterone. This process has been confirmed across multiple species, including humans.
How Much Estrogen Males vs. Females Have
The gap is real but not as dramatic as most people assume. Premenopausal women typically have estradiol levels between 10 and 300 picograms per milliliter of blood, with wide fluctuations across the menstrual cycle. Men generally fall between 20 and 50 pg/mL. That means a man’s estrogen level can actually overlap with a woman’s at the lower end of her range.
After menopause, women’s estradiol levels drop below 10 pg/mL as the ovaries stop producing it. At that point, men on average have higher circulating estradiol than postmenopausal women. The body compensates to some degree: once the ovaries go offline, estrogen production shifts to other tissues like fat, bone, and brain cells. These same tissues produce estrogen in men throughout life.
Four Types of Estrogen
The body makes four distinct forms of estrogen. Estradiol (E2) is the most potent and abundant during the reproductive years, and it’s the form most commonly measured in blood tests. Estrone (E1) is weaker but plays its own role in gene regulation, affecting the menstrual cycle, brain, cardiovascular system, and musculoskeletal health. Estriol (E3) is produced primarily during pregnancy. Estetrol (E4) is made exclusively by the fetal liver during pregnancy.
For everyday health in both sexes, estradiol is the form that matters most. It’s the one responsible for the bone-protective, brain-protective, and cardiovascular effects described throughout this article.
Why Men Need Estrogen for Bone Health
One of the clearest demonstrations that estrogen matters in male bodies comes from bone research. When researchers block aromatase (the enzyme that converts testosterone to estrogen) in men, bone mineral density drops substantially, regardless of how much testosterone is present. In other words, testosterone alone isn’t enough to keep male bones strong. The body needs to convert some of that testosterone into estrogen.
Estrogen deficiency in men disrupts the fine architecture of bone at the structural level, particularly in the dense outer layer called cortical bone. Studies in older men have found a stronger link between low estrogen and fracture risk than between low testosterone and fractures. Men who cannot produce estrogen due to rare genetic mutations develop severe osteoporosis, confirming that estrogen is not optional for the male skeleton.
Estrogen’s Role in Male Reproduction
Estrogen is essential for male sexual and reproductive function, not just female. In men, estradiol helps regulate libido, erectile function, and sperm production. Within the brain, estradiol production increases specifically in areas related to sexual arousal.
Sperm development is modulated by estrogen at virtually every stage, from the hormonal signals that initiate production all the way through to the maturation of individual sperm cells. The relationship is dose-dependent and carefully timed: too little or too much estrogen can both impair fertility. This is one reason why hormonal imbalances in men sometimes affect reproductive health in ways that seem counterintuitive.
How Estrogen Levels Change With Age
In women, the transition is well known: menopause brings a sharp, relatively sudden decline in estrogen as the ovaries shut down production. In men, the picture is different. Testosterone declines slowly and progressively with age, but estrogen levels don’t necessarily follow the same path. Some studies report a gradual decline, while others find estrogen levels in men remain essentially stable over time.
One reason for this is that the rate of aromatase activity, the conversion of testosterone to estrogen, actually increases as men get older. So even as testosterone drops, the body may compensate by converting a larger share of what remains into estrogen. Fat tissue is a major site of this conversion, which is part of why body composition changes with aging can shift the testosterone-to-estrogen ratio.
The practical takeaway is that estrogen remains an active and important hormone in male bodies well into old age, continuing to protect bones, brain cells, and blood vessels long after testosterone levels have started to fall.