Optimize your testosterone-to-estrogen ratio with thyroid

Excess estrogen is known to cause a lot of side effects.

Estrogen is more likely to cause problems when testosterone is low. Therefore it’s best to look at the ratio of estrogen to testosterone.

Although I don’t think there is a best ratio, I do think there are optimal levels for both.

The easiest way to manipulate the testosterone-to-estrogen ratio is by optimizing your thyroid function.

Thyroid hormones and the testosterone to estrogen ratio.

Hypothyroid individuals tend to have lower testosterone and higher estrogen and prolactin.

Subclinical hypothyroidism was associated with a decrease in the levels of serum testosterone and its precursor progesterone… The level of oestradiol was similar in both the groups, suggesting a greater conversion rate of testosterone to oestradiol in subclinically hypothyroid males, in order to maintain the oestradiol levels.” (R)

Hypothyroidism was found to be associated with an increase in the circulating level of total cholesterol and LDL-cholesterol (LDL-C) and a reduction in the levels of progesterone and testosterone, without any change in the serum levels of oestradiol and gonadotrophins. The failure of gonadotrophins to rise could be accounted by a normal level of serum oestradiol in the hypothyroid male.” (R)

The exact cause of sexual dysfunction in hypothyroidism is not clear. It could be attributed to persistent mild hyperprolactinemia as reported in the hypothyroid patients or it could be due to a rise in estrogen to testosterone ratio as reported by us and other or due to a CNS effect.” (R)

Treating hypothyroid individuals with thyroid hormone, T4 and/or T3, reduces TSH and prolactin and increases LH, total and free testosterone and DHT, while increasing the testosterone-to-estrogen ratio (R).

T3 inhibits aromatase in the Sertoli cells of the testes (R). Testosterone also inhibit basal, cAMP stimulated and FSH stimulated aromatase (R). In hypothyroidism, FSH is usually normal, with testosterone being lower, and this leads to great stimulation of aromatase by FSH.

On the flip side, hyperthyroid individuals oftentimes also have excess estrogen, but it’s not due to T4 or T3 stimulating aromatase (R)


If you suffer from excess estrogenic symptoms, have a look at your testosterone, estrogen, DHT, prolactin, TSH and total and free T3.

The optimal amount of estrogen for each person will vary based on estrogen receptor expression and sensitivity as well as the ratio to other hormones, such as progesterone, testosterone, DHT, etc.

A good number to shoot for estradiol is 20-25pg/dl and for testosterone and DHT it would be the upper range of normal.

Optimize thyroid function to improve your hormone levels and ratios.

Get a thyroid panel done to see where the hiccup in the system is.

Related article

The easiest way to optimize thyroid function is to eat a nutrient-dense diet with lots of animal foods, such as meat, organ meat, eggs, shellfish, dairy and fruits.

The production of T4 requires vitamins and minerals. The conversion of T4 to T3 requires selenium, zinc and iron. Be sure to eat foods high in those nutrients as per the testosterone food pyramid.

>1000ng/dl Testosterone: My Step-by-Step Guide on How I Do It Naturally!

2 thoughts on “Optimize your testosterone-to-estrogen ratio with thyroid”

  1. I always find really good health and wellness information that keeps me in tip top condition. But it as not always been that way finding Ray peat and then you who lifts weights and exercises. And generously sends out these newsletters every week l thank you and appreciate the great work cheers Hans 👍


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