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How Much Estrogen does a Woman Really Need?

by Jim Paoletti RPh on 17/11/09 at 5:06 pm

How Much Estrogen does a Woman Really Need?

Historically, it has most often been assumed that when a woman enters perimenopause and begins to experience symptoms which include hot flashes, it means she needs estrogen. However, a woman’s estrogen levels do not decline until the last 6 to 12 months of perimenopause. When she first enters perimenopause, estradiol levels usually rise slightly. The hot flashes that she experiences at this stage of life are not caused by a lack of estrogen.

Elevated FSH Does Not Indicate Estrogen Deficiency

Many health practitioners were taught to measure FSH levels to confirm that estrogen levels were low. However, estrogen has been shown not to be the major controller of FSH. FSH is controlled primarily by inhibin, a hormone produced in the corpus luteum. When a woman does not ovulate, she does not produce a corpus luteum or inhibin, and the FSH rises due to a lack of inhibin, not a lack of estrogen. Progesterone is also produced by the corpus luteum, so elevated FSH is reflective of a decreased production of progesterone. A physiologic amount of progesterone is required to make estrogen work correctly. In early peri-menopause, a woman’s hot flashes are most often caused by a lack of progesterone, not a lack of estrogen.

When Does an Estrogen Deficiency Symptom not Indicate Estrogen Deficiency?

Although progesterone is a key in obtaining optimal effects of estrogen, other hormones may cause or influence the symptoms we often perceive as a lack of estrogen. High cortisol levels can also cause weight gain, irritability, irregular cycles, and hot flashes even in the present of normal estrogen levels. Consistent low cortisol can also cause or aggravate hot flashes. Low thyroid function can cause similar symptoms that appear as estrogen deficiency; insulin resistance can do the same. Over the recent years, one of the largest changes in the approach to obtaining physiologic hormone balance in women is the way estrogen replacement is approached. Since so many other hormone levels affect estrogen and estrogen receptors, correcting other hormone issues have led to further and drastic reduction in the amount of estrogen commonly administered. In other words, if the other hormone or endocrine issues are addressed first, then the amount of estrogen required to treat the assumed “estrogen deficiency” symptoms becomes smaller.

No symptom or set of symptoms guarantees a woman needs estrogen, as some symptoms can be explained by another possible hormone deficiency. Vaginal dryness or atrophy, which almost always indicates a lack of estrogen, can exist when estrogen levels are normal. Vaginal tissues are also supported by testosterone and thyroid, and a significant deficiency in one or both of these hormones can be the source of the problem. Lack of progesterone could result in the estrogen not being effective. Properly assessing estrogen need and assessing response to estrogen therapy requires balancing the other endocrine hormones simultaneously or prior to estrogen administration.

Although most of the time, measurement of estrogen levels via testing is very accurate, there is a small window of time in woman’s life when it may not reliably indicate estrogen need. Estradiol levels begin to fluctuate during perimenopause, with much wider vacillations towards the end of perimenopause. During this period, proper measurement of all other hormone levels along with symptom assessment should be reviewed. The best approach would be to correct deficiencies or issues with progesterone, cortisol, thyroid, insulin resistance, and nutrition or lifestyle, then correlate remaining symptoms with levels, and address estrogen therapy as required.

How Much Estrogen is Just Enough?

Historically women have been given too much estrogen even when they do need estrogen replacement. Excessive estrogen may help control the hot flashes for a month or two, but eventually the symptoms return. A surplus of estrogen causes the same symptoms as insufficient estrogen, just with a slight time delay before the symptoms return. Too much estrogen at first increases the number of estrogen receptors, but after a period of time the body decreases the number of receptors, so the estrogen cannot work properly no matter how much is there.

Premarin® 0.625 mg or Estrace® 0.5 mg, dosages commonly administered for years, are excessive estrogen burden for any woman. The majority of estradiol given by mouth is converted to estrone, another strong estrogen. Estradiol levels resulting from these doses may be at normal premenopausal levels, but estrone levels will be significantly higher than normal. High estrone levels lead to symptoms of estrogen dominance and significantly increase the risk of breast cancer. Premarin® contains 50% estrone, and 5-19% estradiol (along with a bunch of horse estrogens!). The estradiol in it for the most part is quickly converted to estrone, so what the patient is really receiving is a strong dose of estrone. While Premarin® produces normal premenopausal levels of estradiol, estrone levels are usually 7-10 times higher than they should be. Clinicians usually only measure the estradiol level to manage therapy.

Estrace® is bioidentical estradiol, but again the usual doses given by mouth produce too high an estrone level , usually 3-5 times higher than normal.

Topical administration of estrogen is safer and enables administration in a manner where the correct ratio of estradiol to estrone can be accomplished. Topical administration is a very efficient manner to deliver hormones, so compared to the oral route much lower doses are required. But because many practitioners have erroneously assumed that venous blood measurement can be used to determine the amount of topical dosing, doses much higher than physiologic amounts are too commonly used.

Testing Estrogen Levels

Capillary blood or saliva testing must be used with topically applied hormone to get a true representation of the amount of hormone that is being delivered to the tissues where the hormones work. Too often excess hormone is used based on serum testing, then the symptoms return as a result, and then even more hormone is given. Symptoms of too much of any hormone are very, very similar to symptoms of too little of that hormone! If the hormone has worked for a period of time, and is no longer effective, it is usually a good indication that too much hormone has been administered.

Keys to Physiologic Estrogen Replacement Therapy

  • Make sure the patient needs estrogen by correlating symptoms with measurement of levels.
  • Never assume a woman needs estrogen.
  • Always restore progesterone to a physiologic level before assessing how much, if any, estrogen is needed.
  • Test cortisol with a 4 times a day saliva test to help determine adrenal influence on “estrogen deficiency” symptoms. Address as necessary.
  • If symptoms of hypometabolism (hypothyroid) are present, test the TT4, fT4 direct, fT3 direct, TPO and TSH to properly assess. Address appropriately.
  • Check insulin resistance if symptoms indicate and address appropriately.
  • Always start very low on estrogen dosing and make changes slowly.
  • Take steps to ensure safe estrogen metabolism by optimizing liver conjugation, bowel elimination, methylation and glutathione conjugation, and by reducing lipid peroxidase activity.

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10 Responses to “How Much Estrogen does a Woman Really Need?”

  1. avatar


    May 5th, 2012

    hello my name is erica and my mom has been having horrible problems with menopause for many years. She was on a patch for 10 years that gave her more estrogen but it sudden stoped working after she had bladder surgery. Her estrogen levels droped really low and shes been on hormonal replasement theapry for 7 months now shes tryed crem, pills, shot, and the patch again. Nothing seems to help she has had horrible anxiety and some depression plus some night sweats. Ive been looking for answers and we just don’t know what to do anymore. I would greatly appreciate any information on what we can do to get my mom back to where she needs to be.

    Thanks, Erica

  2. avatar

    Brenda Brown

    Dec 18th, 2011

    How would I get in contact with you.
    I would like you to balance my hormones. I have been on a rollercouster for 30 hears. I know I can’t live without them.

    Thank You

  3. avatar


    Sep 8th, 2010

    FSH is follicle stimulating hormone….

  4. avatar

    Jim Paoletti

    Aug 25th, 2010

    For Eileen: Conventional Venus Serum testing is not valid or accurate for hormones applied to the skin, so the resulting doses are most commonly way too high. Your symptoms are caused by too much of the hormones. You need to test your hormones in saliva or capillary blood spot (finger stick)

  5. avatar


    Aug 21st, 2010

    Thank you for this valuable article. The contents need to be shouted from the rooftops. The minute a medical practitioner hears the term HOT FLASH, they immediately place a woman on estrogen when in fact there may be other causes. My understanding is that this could be very dangerous particularly is there is a history of cancer in the family and/or estrogen dominance already in place. My doctor did this and my hot flashes actually worsened from the estrodiol/estriol bioidentical cream that he placed me on. This confirmed that the heat was coming from other origins. I am currently exploring these other sources. Before signing out, I wish to share a recent experience with bioidentical progesterone. I switched from the cream to the pill and my entire system went haywire. Almost immediately my immune system was weakened and my blood sugar levels dramatically increased placing them into pre-diabetic levels. Previously my A1C was 5.8, but after the bioidical pill they increased to 6.0. My sleep is tortuous (awakening every 2 hours at night, difficulty falling sleep, shallow, then battling heat).
    I have been having difficulty finding a medical practitioner who can reverse the damage done, yet given that the pill goes through the liver (i.e, first pass), I suspect it has to do with the liver. I may have been particularly vulnerable as well because my cortisol levels (saliva test were below average.) The point is that this is tricky business and it is new territory even for medical practitioners. Very frightening !

  6. avatar

    hilary stevenson

    Dec 19th, 2009

    Message for Annick Mussche: I hope you have found Thierry Hertoghe , a wonderful endocrinologist who lives in Belgium! I dont have his details but am sure you can google him. Best wishes.

  7. avatar


    Nov 19th, 2009

    At the beginning of sex I am lubricated, but seconds later it seems like I dry up. Which makes intercourse a little painful…Is there anything I can take or do for this?
    Thank You

  8. avatar


    Nov 19th, 2009

    I am 60 years old and on BHRT Biest 4.5mg Prog. 250mg Test 2mg
    I use this daily as a topical cream. What are the effects of too much of either of the hormones? I have breast cysts and sometimes feel soreness more than other times. My doctor has blood tests done and shows my estradiol still low.. Is that an indicator that I’m not getting too much of the hormones? or is my formula still not balanced? I take thyroid hormone and iodine 6mg…too much thyroid hormone after awhile of build up tends to give me palpitations…How can I adjust to this as I have more energy on the higher amount of 30mg of thyroid a day. Thank you for a reply.

  9. avatar

    Ann Haffner

    Nov 19th, 2009

    What do the initials FSH stand for?

  10. avatar

    Annick Mussche

    Nov 19th, 2009

    I am belgian and live in Brussels. I have found your information very interesting. I am 55 years old and have gone 7 months without periods and have been experiencing the above symtoms on and off. I do not take any hormone replacement at all, although I did use progesterone cream on and off for a couple of years ending in March.
    Would you know of any doctor in Belgium who is has knowledge on hormonal distrurbances? That would be my miracle.
    Thank you for this wonderful article and have a great day.
    Regards, Annick Mussche