Every woman is born with all the eggs she’ll ever have.
At birth, there are roughly 1–2 million oocytes (immature eggs) stored in the ovaries.
By puberty, that number drops to around 300,000–400,000, and only about 400–500 will ever fully mature and be released during ovulation.
As we move through our 30s and 40s, both the quantity and quality of remaining follicles decline.
This decline alters the normal balance of reproductive hormones - especially oestrogen, progesterone, and follicle-stimulating hormone (FSH) - leading to the hormonal fluctuations that mark perimenopause.
So when symptoms like irregular cycles, sleep disruption, or mood changes appear, it’s not “sudden.” It’s your biology shifting gears - a gradual, natural transition driven by the finite nature of those eggs.
I hope that understanding the why behind these changes helps with fear or worry about what's happening within your body during this life stage, and in this week's episode we're talking all about hormones.
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