Estrogen

What is Estrogen?

Estrogen, or oestrogen, is the primary female sex hormone. It is responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens in females that have estrogenic hormonal activity: estrone, estradiol, and estriol. The estrane steroid estradiol is the most potent and prevalent of these.

Estrogens are synthesized in all vertebrates[1] as well as some insects.[2] Their presence in both vertebrates and insects suggests that estrogenic sex hormones have an ancient evolutionary history. The three major naturally occurring forms of estrogen in women are estrone (E1), estradiol (E2), and estriol (E3). Another type of estrogen called Estetrol (E4) is produced only during pregnancy. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males compared to females, estrogens nevertheless also have important physiological roles in males.

 

Estrogen Levels in Women

  • Estrone is considered a weaker form of estrogen. It is typically produced by special belly fat cells, and is the major estrogenic form found in naturally-menopausal women who are not taking HRT.
  • Estradiol is the major estrogen produced by ovaries and is the strongest (the most effect for the least quantity) form. Estradiol is the “active” estrogen—the one that is capable of the fullest range of estrogen effects because it is the one that actually goes out there in our tissues and sockets into estrogen receptors and causes estrogen effects.
  • Estriol is a metabolic waste product of estradiol metabolism that can still have some effects upon a limited number of estrogen receptors. It is formed in the liver and is 8% as potent as estradiol and 14% as potent as estrone.
  • Progesterone’s role in the body is closely linked to that of estrogen, in that in many ways it seems to oppose, or counterbalance, the action of estrogen. In fact, many receptors in the body can be occupied by either hormone. When progesterone is occupying an estrogen receptor, the action that estrogen would cause if it were there instead can be blocked. For every receptor that is occupied by progesterone, a molecule of estrogen is thus freed up to do its work elsewhere. In other words, putting progesterone into the system effectively raises the amount of estrogen available to do estrogen-only tasks while at the same time some of those estrogen tasks may go unperformed or underperformed because of progesterone’s occupation of those receptors.
HRT

Hormone replacement therapy 

Medications containing female hormones to replace the ones the body no longer makes after menopause — is sometimes used to treat common menopausal symptoms, including hot flashes and vaginal discomfort.

What are the benefits of hormone therapy?

The benefits of hormone therapy depend, in part, on whether you take systemic hormone therapy or low-dose vaginal preparations of estrogen.

  • Systemic hormone therapy. Systemic estrogen — which comes in pill, skin patch, gel, cream or spray form — remains the most effective treatment for the relief of troublesome menopausal hot flashes and night sweats. Estrogen can also ease vaginal symptoms of menopause, such as dryness, itching, burning and discomfort with intercourse.

  • Low-dose vaginal products. Low-dose vaginal preparations of estrogen — which come in cream, tablet or ring form — can effectively treat vaginal symptoms and some urinary symptoms while minimizing absorption into the body. Low-dose vaginal preparations do not help with hot flashes, night sweats or protection against osteoporosis.

What are the risks of hormone therapy?

In the largest clinical trial to date, a combination estrogen-progestin pill (Prempro) increased the risk of certain serious conditions, including:

  • Who should consider hormone therapy?

    Despite its health risks, systemic estrogen is still the most effective treatment for menopausal symptoms. The benefits of hormone therapy may outweigh the risks if you’re healthy and you:

    • Experience moderate to severe hot flashes or other menopausal symptoms
    • Have lost bone mass and either can’t tolerate or aren’t benefiting from other treatments
    • Stopped having periods before age 40 (premature menopause) or lost normal function of your ovaries before age 40 (premature ovarian insufficiency)
     

    Women who experience early menopause, particularly those who had their ovaries removed and don’t take estrogen therapy until at least age 45, have a higher risk of:

    • Osteoporosis
    • Heart disease
    • Earlier death
    • Parkinson’s-like symptoms (parkinsonism)
    • Anxiety or depression
 

References:

  • https://en.wikipedia.org/wiki/Estrogen
  • https://www.mayoclinic.org/diseases-conditions/menopause/in-depth/hormone-therapy/ART-20046372
  • https://surmeno.blogspot.com/2006/07/three-estrogens-estradiol-estrone.html
  • https://www.renewmetoday.com/estrogen/
  • https://www.contemporaryobgyn.net/menopause/low-dose-vaginal-estrogen-cvd-and-cancer-there-risk
  • http://motherhoodinpointoffact.com/