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.

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.

Methylation is basically your body adding a small chemical group (one carbon + three hydrogens = a “methyl group”) to another molecule. Sounds tiny. But that little shift can completely change how your body functions.

PMS (pre-menstrual syndrome) refers to a group of physical and emotional symptoms that a woman may experience in the week or so leading up to the beginning of her menstrual cycle (when she starts menstrual bleeding) and subsides within a few days of menstruation.  

If you’ve managed to make it through most of your adult years with regular, “normal” periods but now suddenly find yourself with heavy or irregular bleeding, it can be rather alarming.