Who you callin’ weak?
Just because estriol is known as the weak sister of the estrogen trio (estradiol, estrone and estriol), don’t be fooled. Maybe you’ve heard of the “butterfly effect,” in which “small variations of the initial condition of a dynamic system may produce large variations in the long term behavior of the system.” In other words, sometimes something small or weak can make a major difference. That definitely applies to the use of estriol in bioidentical hormone replacement therapy!
Estriol
Let’s start at the beginning: Three forms of estrogen occur naturally in a woman's body. The ovary produces a form named estradiol, which is converted into another important estrogen called estrone. Estriol is yet another form of estrogen metabolized from estradiol, weaker than the other two, but still active. Although estriol is most commonly linked to pregnancy since it is produced in the most measurable amounts at that time, it is still present throughout a woman’s lifetime at varying levels.
Because estriol has been considered a by-product of another from of estrogen and thus too weak to matter, it has been largely overlooked as a beneficial piece of the hormone pie. However, studies suggest that it can help reduce a variety of symptoms associated with perimenopause and menopause, including:
- Hot flashes
- Vaginal dryness
- Bone density
In addition, research points to the benefits of estriol for heart health, post-menopausal urinary tract health and protection against osteoporosis.
Estriol’s strength is actually found in its weakness. Tests show that while relieving the symptoms of perimenopause and menopause, estriol doesn’t seem to increase the risk of breast cancer. This is because estriol binds to the estrogen receptors on the breast cells, but it has much weaker activity. Therefore, it actually blocks the stronger estradiol from binding to those cells and subjecting them to the higher estrogenic activity which has been shown to be protective against breast cancer. And for women who have difficulty tolerating stronger estrogens for the treatment of hormonal imbalance due to aging, estriol is often the right choice.
For women experiencing symptoms of perimenopause or menopause, your BodyLogicMD doctor may test your estriol levels. Because they fluctuate throughout the day, the most reliable way to measure estriol levels is through 24-hour urine collection.
