I want to take this week’s blog to discuss hormone terminology as well as the basic physiology (function) of our ovaries.
There are a ton of terms out there regarding hormones and I want to clear some of that up. Some of the terms can be applied to multiple hormones (or products) and hormones/products may be accurately described by multiple terms.
What does bio-identical mean?
Bio-identical is a term that refers to hormones that are made to mimic our natural hormones. They are made to look just like what our bodies make or made in the past in the case of menopause.
While the Menopause Society will state that the term “bio-identical” means different things to different people, I don’t think this is an accurate or acceptable understanding.
People may interpret bio-identical to mean exactly what I said above which is accurate.
Others may interpret bio-identical to mean the medication is compounded, which will be discussed below. While compounded can be used, “bio-identical” and “compounded” are not one in the same. They do not mean the same thing.
Examples of bio-identical are:
Estradiol 17beta: mimics one of our natural estrogens (we have three: estrone, estradiol, and estriol)
Micronized progesterone: mimics our natural progesterone
These can either be delivered as compounded medications or as prescriptions. I utilize both avenues.
What does synthetic mean?
Synthetic means the “hormone” is manufactured and is not structurally or chemically identical to what we naturally make. This is in opposition to bio-identical.
Examples of synthetic are:
Birth control pills: made with different doses of ethinyl estradiol which is synthetic and various forms of synthetic progestin (norethindrone, for example)
Hormonal IUD (intrauterine devices): releases levonorgestrel, a synthetic progestin
Among other types of birth control and hormone replacement therapy
What does compounded mean?
Compounded is referring to the preparation of the medication, in this case hormone therapy, though there are many medications that can be made this way.
This would be an alternative preparation to a standard prescription therapy.
The benefits of compounding include less “filler” products like oils. A great example of this is compounded progesterone that does not include peanut oil, while prescription progesterone frequently is made with peanut oil.
What do our hormones do?
Let’s talk about the basic function of our ovaries and how a normal menstrual cycle is really a dance of hormones.
Day 1 of bleeding, so the first day of the period, is considered the start of the cycle. Each additional day is counted as the next day of the cycle (2, 3, 4, on and on) until the next period happens, where it starts over at day 1.
What is happening in a normal cycle?
At the start of a period, hormone levels (both estrogen and progesterone) are actually at their lowest.
As we progress through days of bleeding, the level of Follicle Stimulating Hormone (FSH) is rising. This hormone is secreted from the pituitary gland in our brain sending a signal to our ovaries.
In response, our ovaries produce increasing amounts of estrogen (estradiol form) which is rising each day.
These hormones feed into one another as they both increase, leading to a surge of Lutenizing Hormone (LH). Why? They are increasing to develop follicles, the ovarian cysts that are growing in this phase of the cycle, and one follicle will be The Chosen One for the month. The Chosen One is the dominant follicle: the one that will ovulate to become fertilized.
Once The Chosen One has ovulated (around day 14 in a 28 day cycle), progesterone levels will now be higher than estrogen. Estrogen levels will start to fall.
Progesterone levels are rising to support a developing pregnancy (remember we ovulated to get fertilized). If the egg got fertilized, it will travel down the fallopian tube where it lands and implants in the uterus.
If pregnancy does not happen, progesterone levels will also drop. This drop is what triggers the period to start.
What happens in menopause?
In menopause, the ovaries are no longer responding to the signals from the brain (FSH). They still make tiny amounts of hormones but these typically aren’t detectable on standard lab values.
What would I expect to see on lab work?
For someone who is menopausal, I expect the blood level of estradiol to be low. The reporting of this may differ depending on the lab but may be reported as <25.
I would expect the FSH level to be high. The brain doesn’t get it. The ovaries aren’t releasing the estradiol that the brain is asking for, so the brain continues to pump out FSH trying to get the ovaries to listen. The FSH level again will vary between labs but will likely be above 25.
Resources:
I actually wrote this entry completely from my brain without looking at any resources, but I suppose if I have to cite something, it’s the book below.
Some of the information contained in this article is the result of my training, medical knowledge, and personal experience without a specific source to be cited.
Menopause Practice, A Clinician’s Guide: 6th edition. The North American Menopause Society. (Now called The Menopause Society)
