What Is Actually Happening in Your Body

The ovarian clock

A female infant is born with approximately 300,000 ovarian follicles — each containing a single egg. From birth onward, these follicles are gradually depleted. By around age 37, roughly 25,000 remain; by menopause, few or none are left. This is not a disease or a deficiency — it is the natural lifespan of the ovary.

As follicle numbers decline, the ovaries produce less estradiol (the primary form of estrogen) and less inhibin (a hormone that keeps the pituitary gland in check). In response, the pituitary releases increasingly high levels of follicle-stimulating hormone (FSH) in an effort to stimulate the dwindling follicles.

The role of estrogen in your body

Estrogen receptors are found in virtually every organ system, which is why estrogen loss has such far-reaching effects. Beyond its role in the reproductive system, estrogen:

• Blood vessels — Maintains the elasticity and health of blood vessel walls.
• Cholesterol — Helps regulate cholesterol levels, keeping LDL (“bad”) cholesterol in check and maintaining HDL (“good”) cholesterol.
• Bones — Protects bone density by slowing the natural process of bone resorption.
• Brain — Influences brain function, mood regulation, and memory.
• Vaginal & urethral health — Keeps vaginal and urethral tissues moist, elastic, and healthy.
• Body composition — Helps regulate body composition, including fat distribution.

What about androgens (testosterone)?

Women produce testosterone — in fact, before menopause, women’s bodies produce more testosterone than estrogen (though in much smaller absolute amounts than men). Testosterone in women is made by both the ovaries and the adrenal glands, and it contributes to energy, muscle mass, bone density, and sexual desire.

Testosterone levels do not drop sharply at natural menopause — they have been declining gradually since a woman’s late 20s and early 30s. Natural menopause does not cause a sudden testosterone deficiency.

Surgical menopause (removal of both ovaries) is a different story: it causes an immediate, significant drop in testosterone, which is why women who undergo oophorectomy often experience more abrupt and pronounced changes in libido and energy.