If you've ever been told that progesterone “doesn’t matter” unless you have a uterus… or that your symptoms after starting progesterone HRT must mean “your dose is too high”… or that transdermal progesterone doesn’t work—then this article is for you.

If you’ve ever thought about hormone therapy but immediately felt a wave of fear—because you were told it causes cancer—you’re not alone. One of the most common things I hear from women is: “I was told I can’t do hormones because of breast cancer,” Or, “My doctor said hormones are dangerous—especially with my family history.”

Progesterone plays a critical role in balancing estrogen’s effects on the uterine lining. In a normal menstrual cycle: Estrogen builds up the uterine lining (called the proliferative endometrium). Progesterone comes in after ovulation and stabilizes and matures that lining, converting it into a secretory endometrium—a plush, nutrient-rich environment ready for a fertilized egg to implant.