Progestogens and Progestins and Progesterone. Oh, my!
Understanding the Second Part of the Hormone Menoverse.
While the estrogen in menopause hormone therapy (MHT) does the heavy lifting to relieve symptoms and protect the bones, when given by itself, estrogen significantly raises the risk of pre-cancer and eventually cancer of the uterus. These precancerous changes can start quickly, even within a year (read more about that risk here), so this is where the group of chemicals known as progestogens comes in because they oppose the effect of estrogen on the lining of the uterus and prevent this cancer. In this article, I will focus on the progestogens–what they are, if they are “plant-based” or not, the difference between products, why compounded products are bad, how they are given, and a few nuances behind selecting the best option.
This piece is part of the “Into the Hormone Menoverse Series,” and you can catch up on everything that’s been written to date at the Table of Contents, here, which I update with each post and provide links so you don’t have to go searching for what you want.
The Background
At the start of each menstrual cycle, the developing follicle produces estrogen, which, among other things, causes the lining of the uterus (the endometrium) to grow. With ovulation, the corpus luteum produces progesterone, which prepares the lining for implantation. One of progesterone's jobs (as it were) is to slow the effect of estrogen on the endometrium (it’s a bit like putting the brakes on estrogen). When there isn’t enough progesterone, for when people ovulate infrequently, the estrogen can cause uncontrolled growth of the endometrium which can result in irregular periods and, over time, can lead to cancer.
Endometrial cancer from menopausal hormone therapy (MHT) is but one of the awful legacies of the Feminine Forever era. The book Feminine Forever, written in 1966, was funded by Pharma and disguised patriarchal beliefs as feminism. It positioned menopause as a disease and the worst disease imaginable: one that made women unattractive to men. The book was all about estrogen being a ticket to eternal youth and hotness, so there was an estrogen gold rush, and within a few years, cases of endometrial cancer in the United States surged. It became clear that people with a uterus who were taking estrogen needed protection from cancer, and the main class of drugs that do this are called the progestogens, but another option is a selective tissue receptor modulator called bazedoxifene (read more about that here).
What is a Progestogen?
Progestogens are a class of drugs that act like progesterone. They include progesterone, which is natural, meaning found in nature, and a group of drugs called progestins, which are synthetic, meaning they are novel compounds not found in nature. Being synthetic does not make them bad or good; synthetic is simply a chemical description. The same thing about safety can also be said for compounds found in nature. There are plenty of natural things that have negative side effects or can even kill you. If you walk out my front door there is a massive wall of a highly toxic plant, oleander (it grows like a weed here, and, unsurprisingly, is one of the few pretty flowers that the deer ignore). However, the word “synthetic” has unfortunately become some kind of secret code for “bad” or “harmful,” but any provider or “hormone influencer” that uses the word synthetic as a hormone insult is either purposely misleading you, is willfully ignorant, or is not able to understand the basics. I don’t expect the public to know about progestins, but I do expect someone advertising themselves as a health care provider or a “hormone guru” to have that knowledge.
Progestins were designed for the first birth control pill. While progesterone suppresses ovulation (this is how the body prevents another conception during early pregnancy), it proved too weak for the job when given orally. By tinkering with the hormone testosterone, researchers designed a class of hormones that we now know as progestins that were absorbed well when taken by mouth, were better than progesterone at suppressing ovulation, and also better than progesterone at opposing the effect of estrogen on the lining of the uterus, which meant they reduced abnormal bleeding with oral contraceptive pills.
While the potency of a progestin was needed for hormonal contraception, progesterone is typically enough to protect the uterus from the estrogen in MHT.
Who Needs a Progestogen?
If you have a uterus and are taking estrogen in MHT, you need a progestogen or bazedoxifene. Here we will focus only on progestogens.
Needing a progestogen includes if you start MHT before menopause, as some people do because hot flashes can start before the last menstrual period. If you still have periods, the progesterone from ovulation cannot be relied upon to protect your uterus