Good Oestrogen / Bad Oestrogen


Woman are scared of oestrogen, because it causes oestrogen dominance, and because it carries a cancer risk. But is that the whole story with oestrogen? Oestrogen is extremely important for mood and well-being, so we don't want to avoid it completely. In fact, oestrogen may not be as bad for you as you think. (Please see Lara's blog post In Defense of Estrogen.)

According to hormone researcher Dr Phyllis Bronson, oestrogen has been given a bad rap. The real culprit in the 2002 Women's Health Initiative Study was not oestrogen, she says, but the artificial progestins used in all parts of the study. (1) The physiological difference between human progesterone and artificial progestin is extremely significant. Artificial progestins damage the cardiovascular system and increase breast cancer risk, and this confuses the results of any study of conventional hormone replacement. (Most readers of this website understand the distinction between bio-identical progesterone and progestin. Although many doctors do not.)

Furthermore, oestrogen has many faces. Some oestrogens are significantly more cancer causing than others. Some oestrogens, such as oestriol, have even been shown to be cancer-protective. (2) Even the strong oestrogen, oestradiol, has been shown to prevent cancer from growing in some cases. (3)

The most risky oestrogens are oestrone, and oestrogen metabolites such as 4- and 16-hydroxyestrone.  These metabolites become elevated when liver function is compromised. They can be tested, and if they're high,  they can be effectively eliminated from the body with nutritional supplements, such as cruciferous extract DIM.

Oestradiol for mood and sleep

By completely avoiding oestrogen, women may miss out on the benefits that oestrogen supplements can have for mood and sleep. One oestrogen in particular, 17-beta estradiol, is a powerful mood-enhancer. According to Dr Bronson, there is relatively little cancer risk from oestradiol itself. (The biggest risk comes from oestradiol's metabolites (4 and 16 oestrone), which can be measured and managed.)

That is not to say that oestrogen should be the first choice for mood enhancement. There are many nutritional and lifestyle factors that should be considered first. If the choice is between pharmaceutical antidepressants and oestradiol, however, the evidence favours oestradiol. Pharmaceutical anti-depressants such as SSRI's have significant side effects, such as weight gain, low libido and an increased risk for diabetes.

To replace oestrogen or not?

The body's own oestrogen production can be encouraged by many natural methods, even in post-menopausal women. (Oestrogen does not drop to zero at menopause. In a healthy woman, it drops to about 30% of her original level.)

Some women are more likely than others to need hormone supplementation. These include those who are without ovaries, and those who have a long history of birth control pill use. Also, women with insufficient adrenal hormones will experience a greater drop in oestrogen. That is why the adrenal hormone DHEA is such an effective treatment for menopausal symptoms and infertility. DHEA converts to oestradiol.

Should any hormone be supplemented?

Before you supplement hormones, try diet and lifestyle first. Do NOT smoke. Reduce your intake of alcohol and sugar. Get enough rest, and enough sleep.  Eat well including vegetables, protein and healthy fat.

If you feel that you might need natural hormone supplements, then assess for DHEA and progesterone deficiency first. If they are low, then you can use herbs and supplements to increase their production. If that is not enough then consider supplementing with natural progesterone or DHEA.

If progesterone and DHEA are not enough, then you need to consider oestrogen. The safest oestrogen is oestriol. Oestriol is effective for symptoms and is used widely in Europe. Is is protective against cancer.

If all else fails, then consider using small doses of the stronger oestrogen called oestradiol. This may be a conventional oestrogen patch or gel, or it may be a bio-identical formula called "bi-est".  If oestradiol in any form is used, then it should be taken together with Natural ProgesteroneArtificial progestins should be strictly avoided.

If oestrogen is used, urinary hormone levels should be assessed. 


(1 ) Bronson, PJ. In Defense of Estrogen. Letters to the Editor. Townsend Letter for Doctors. 2008; 34:85-87

(2) Lemon, H.M. et al. Inhibition of Radiogenic Mammary Carcinoma in Rats by Estriol or Tamoxifen.Cancer 1989; 63(9):1685-1691

(3) Ellis MJ, et al. Lower-dose vs high-dose oral estradiol therapy of hormone receptor-positive, aromatase inhibitor-resistant advanced breast cancer. JAMA 2009; 302(7): 774-80.



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