Have you ever sat there and wondered why we use hormonal birth control and how it works? Ever been confused about the different types of hormones needed to help prevent pregnancy? Conflicting information can be found everywhere you look and depending on what country you live in, even the hormone names can be different.
For example, Estrogen is spelled as Oestrogen in some countries. When looking online you might see if referenced as either, even though it’s the same thing. Confusing right?
Here are the basics that you need to know:
- Estrogen and Progesterone are the primary sex hormones that women need to control their ovulation, menstruation and reproduction.
- Both are produced naturally by the body, mainly in the ovaries.
- Both have synthetic man-made versions that are used in birth control and hormone replacement therapies.
What Is Estrogen
Estrogen is a group of hormones that are important for the sexual and reproductive development in women. They are often referred to as female sex hormones. “Estrogen” is an umbrella term used to refer to all of the chemically similar hormones in the Estrogen group. These Estrogen based hormones include Estrone, Estradiol and Estriol. It’s worth noting that Estradiol is found primarily in women of reproductive age. Different forms of Estriol and Estradiol are used in birth control. Estriol can also be referred to as E3 and Estradiol as E2. These forms of Estrogen are often found in birth control methods that use hormones as a way to control menstruation and prevent pregnancy.
Estriol (E3) is a naturally occurring form of the main female sex hormone Estrogen
Estradiol (E2) is the predominant form of Estrogen that is produced in the reproductive years.
How does Estrogen work?
In women, Estrogen is produced mainly in the ovaries, with a little help from fat cells and the adrenal glands. Estrogen is responsible for the development of many female characteristics like breast, underarm hair and pubic hair. Therefore Estrogen is an important hormone during puberty when girls start to develop these adult female characteristics. (These characteristics are known as secondary sex characteristics).
Once a girl has experienced her first period, Estrogen helps to regulate the menstrual cycle. It does this during the first part of the cycle by aiding and controlling the growth of the uterine lining. Every month, the lining strengthens in anticipation of receiving a fertilized egg which will lead to pregnancy. If there is no fertilized egg to attach itself to the uterus then the Estrogen levels decrease sharply, leading to a breakdown of the uterine lining. This is when menstruation takes place and the woman starts bleeding. If the uterus receives a fertilized egg, the lining of the uterus does not break down. The Estrogen hormones work together with the Progesterone hormones so ovulation and menstruation stops so the pregnancy can develop.
Estrogen works hard for your body. As well as maintaining the uterine lining, it controls lactation and other changes in the breasts during adolescence, during pregnancy and after birth.
Estrogen is also instrumental in bone strength and formation. Bones naturally break down and rebuild : it’s a natural process. Estrogen works with vitamin D, calcium and other hormones to do this. However as a woman gets older, Estrogen levels start to decline and the natural process of bone rebuilding slows down. By post-menopause, most women break down more bone than is produced leading to weak bones and Osteoporosis. Cleveland clinic estimates that post-menopausal women are 4 times more likely to develop the bone disease than men in later life. This is because me do not suffer the same hormonal drop as women do when they go through “the change of life”.
Estrogen plays an important role in blood clotting. Part of this function relates to the vagina. Estrogen is responsible for maintaining the strength and thickness of the vaginal wall and the urethral lining. It also controls vaginal lubrication. Many menopausal women suffer from vaginal atrophy, which means dry vagina. This is down to lowering hormone levels.
Low levels of Estrogen can result in miscarriage. During pregnancy, most of the Estrogen needed is produced in the form of Estriol by the placenta. Without the help of the placenta the body does not have enough Estrogen production to see a healthy pregnancy full term.
According John Hopkins Medicine Estrogen affects everything from skin, hair, mucous membranes, pelvic muscles, to the brain, and even mood swings so it’s no coincidence that low Estrogen levels are linked with a decline in these areas of female health.
As you can see from the above explanations, Estrogen is very much a woman’s hormone, even though men do have Estrogen in the blood steam as well. It’s actually thought to be instrumental in sperm count levels but apart from that Estrogen does not affect men in the same way as it affects women primarily because men don’t menstruate.
Changes in Estrogen levels
Like all hormones, Estrogen deficiency or Estrogen dominance can cause side effects. Women do need Estrogen but it’s a stimulant hormone and too much of it can cause as much havoc as too little of it. Estrogen levels naturally increase during puberty and during pregnancy to help with body development and pregnancy maintenance. Menopause, hypogonadism (or diminished function of the ovaries) and polycystic ovarian syndrome can cause Estrogen levels to rise or fall. Extreme exercise and anorexia can also cause a decrease in Estrogen levels because women with low body fat may not be able to produce adequate amounts of Estrogen. If you are concerned about your Estrogen levels then get them tested with your doctor!
Medications with Estrogen
Estrogen is found in most oral birth control pills in synthetic form, along with the synthetic form of Progesterone. Both of these hormones are important for birth control but you can get birth control with one and not the other. Typically, Estrogen helps stop ovulation during pregnancy. Birth control pills use a synthetic form of Estrogen to mimic this effect, preventing ovulation from taking place. No ovulation means that no egg is released and so cannot be fertilized by the sperm.
During menopause and after menopause, many women use a medication called hormone replacement therapy to help reduce the symptoms and side effects of hormonal imbalance caused by menopausal changes. It’s often shortened to HRT. HRT normally contains Estrogen by itself or in combination with Progesterone and it can greatly help reduce symptoms like hot flashes, vaginal dryness and night sweats as well as mood swings and anxiety. In 2002, a study by the Women’s Health Initiative showed that HRT caused an increased risk of developing breast cancer, stroke and blood clots. For this reason many women started trying to avoid it. For others, the risks far outweigh the benefits. It’s the same with birth control containing Estrogen. While the risk of breast cancer might slightly increase, protecting from unplanned pregnancy far outweighs the risk of what might happen in future years.
All women taking birth control and hormone replacement therapy are encouraged to go for regular check-ups with their doctor and regular blood testing to make sure they are within the normal and healthy boundaries. It’s also not advisable to stay on birth control or HRT for long periods of times in one go. After a few years it’s best to take a break, where possible and let the hormones in your body regain their natural balance.
The role of Estrogen in cancer
Don’t panic about breast cancer caused by using birth control or HRT. Hormone receptor positive breast cancers are sensitive to Estrogen, this is a fact. This means that Estrogen helps them to grow, it does not mean they are a direct cause of developing breast cancer. People with diagnosed with breast cancer should stop taking birth control or HRT right away. Instead they should focus on taking hormone treatments that lower Estrogen levels or even block Estrogen production. This can help to slow the cancer’s growth and prevent cancer recurrence after surgery.
Estrogen hormones in birth control
Here are some formations of Estrogen that are found in birth control. They might have different names but they are all Estrogen based.
Estradiol Hemihydrate is used in these birth control medications: Activelle, Angelique, Estrofem, Eviana, Evorel, Evorel Conti, Evorel Sequi, Novofem, Vagifem.
Ethinylestradiol is a synthetic version of the natural female sex hormone Estrogen, also called Estrogen. It is used in these birth control medications: Belara, Diane, Evra, Mercilon, Microdiol, Harmonet, Microgynon, Minesse, Gynera, Nuvaring, Yasmin, Yaz, Seasonique. (Sometimes this Estradiol hormone is spelled slightly differently. It can be one word like we say or it can be written as two words Ethinyl Estradiol.
Estradiol Valerate is used in the birth control Progyluton.
What is Progesterone?
Progesterone is a Progestogen. Progestogens are a group of steroid hormones found in the blood stream. Progestogens like progesterone are mainly produced in the ovaries; it’s primarily secreted by the corpus luteum during the second half of the menstrual cycle but the ovaries and adrenal glands have their own production as well. Progesterone is very important when it comes to regulating the menstrual cycle and supporting the first trimester of pregnancy.
During the menstrual cycle the ovarian follicles in the ovary release an egg. This is called ovulation and it happens half way through your monthly cycle : normally on or around day 14. After the egg has been released from the ovarian follicle that helped it to grow the remaining follicle forms a structure called corpus luteum. The corpus luteum then releases Progesterone and Estradiol hormones (Estradiol is a form of Estrogen hormone). The role of Progesterone is to help the body prepare for pregnancy should the released egg get fertilized. In the event that the egg is not fertilised, Progesterone levels fall. This happens because the corpus luteum breaks down and a new menstrual cycle begins.
Progesterone is vital for seeing a pregnancy into its second trimester. During the early stages of pregnancy, Progesterone stimulates the growth of blood vessels that supply the lining of the uterus (known as the endometrium) so it strengthens enough to hold onto the fertilized egg. Progesterone stimulates the glands and helps your body to secrete nutrients vital for nourishing your fertilized egg. Once it’s been implanted into the uterus lining it’s referred to as an embryo. Without Progesterone The lining of the uterus needs good levels of Progesterone in order to strengthen the uterus lining and allow for the fertilized egg to successfully implant. The corpus luteum continues to support the pregnancy with Progesterone production until the placenta forms and takes over progesterone production. The take-over of the placenta indicates the end of the first trimester and the 12 week scan performed confirms that the pregnancy is viable. Progesterone is also essential for your fetus. (once the embryo has become fully established it’s referred to as a fetus). It helps the fetus develop and it also helps your body adjust to impending motherhood. Breast tissue, lactation function and pelvic wall muscles are all affected by Progesterone. Progesterone levels continue to rise during pregnancy until the baby is born.
How is Progesterone controlled?
Natural Progesterone production is mainly controlled by the corpus luteum. How does the corpus luteum form? A surge in production of the luteinising hormone by the pituitary gland in the brain triggers the release of the egg from the ovarian follicle in the ovary which then leads to the creation of corpus luteum. As discussed before, the corpus luteum helps prepare the body for pregnancy. If no pregnancy occurs then the production of Progesterone decreases along with the breakdown of the corpus luteum and you start bleeding.
If the egg is fertilized by the sperm and implants into the lining of the uterus then an embyo forms. The embryo is surrounded by cells that protect it by secreting a hormone called Human Chorionic Gonadotrophin (HCG). It is similar to luteinising hormone and helps makes sure that the corpus luteum keeps producing the Progesterone it needs and doesn’t break down. Eventually these cells become the placenta.
What happens if I have too much Progesterone?
Generally having too much Progesterone does not cause any side effects and it is not dangerous. In fact, as discussed, lots of Progesterone is essential for pregnancy. A condition called congenital adrenal hyperplasia is connected to high Progesterone levels. They don’t cause it though. Actually, it’s the other way round. The condition causes the Progesterone levels to rise.
Hormonal birth control almost always contains some level of synthetic Progesterone. Sometimes the birth control is solely Progesterone and sometimes it is combined together with Estrogen. When used in birth control, Progesterone helps to prevent ovulation so the egg is not released by the ovary and no fertilization can take place.
Hormone replacement therapy used by many menopausal women also contains Progesterone. During menopause and the peri-menopause years the menstrual cycle starts becoming irregular and then stops completely. Along with this goes good levels of Progesterone production. Low Progesterone levels can cause all kinds of side effects like hot flashes, mood swings, night sweats, weight gain and many, many more. The added Progesterone menopausal women receive when taking hormone replacement therapy helps relieve these side effects without interfering with the body’s natural cessation of menstruation.
What happens if I have too little Progesterone?
Menopausal women have low Progesterone levels but it’s also possible to have these earlier on in life. Low Progesterone levels in younger women can cause painful cramping, severe PMS, irregular and heavy menstrual bleeding.
Polycystic ovarian syndrome is also affected by low Progesterone levels. PCOS occurs when the ovarian follicle fails to release the egg during the time of ovulation. When no egg is released the corpus luteum doesn’t know what to do and not enough Progesterone is produced.
Early term miscarriages can occur during the first trimester if you don’t have enough Progesterone to support the embryo/fetus until the placenta forms and aids Progesterone production. Premature labor can occur if the placenta does not produce enough Progesterone. Often doctors prescribe high risk pregnancies doses of synthetic Progesterone to help delay the onset of labor.
In birth control synthetic forms of the Progesterone hormones are used : The synthetic version is referred to as Progestins. Even though it is synthetic and not naturally made by the body the make-up of it is compatible and the body reacts to it well as an added form of Progesterone. This is because it has the same progestogenic effects as Progesterone. Synthetic Progestogens include active ingredients like Norethisterone, Desogestrel, Cyproterone, Norelgestromin, Gestodene, Levonogestrel and Drospirenone.
Progesterone in birth control
Here are some variations of Progesterone that are found in birth control.
Norethisterone Acetate is used in these birth control medications: Activelle, Eviana, Evorel Conti, Evorel Sequi, Novofem and Primolut nor.
Drosperinone is used in these birth control medications: Angelique, Yasmin and Yaz.
Chlormadinone Acetate is used in the birth control Belara.
Desogestrel is used in these birth control medications: Cerazette, Mercilon and Microdiol.
Cyproterone acetate is used in the birth control Diane.
Progesterone is used in the birth controls Endometrin and Utrogestan.
Norelgestromin is used in the birth control Evra.
Gestodene is used in these birth control medications: Harmonet, Minesse and Gynera.
Levonorgestrel is used in these birth control medications: Microgynon, Microlut, Seasonique, Mirena and Postinor.
Norgestrel is used in the birth control Progyluton.
Etonogestrel is used in the birth control Nuvaring.