How to Lower Estrogen

High estrogen can contribute to heavy periods, breast pain, fibroids, and premenstrual mood symptoms. It can also suppress thyroid function and increase the risk of breast cancer.

To lower estrogen, you need to understand all the types of estrogen and why they’re high.

The many types of estrogen

Estrogen is not one thing. Instead, estrogen is a generic term that can refer to:

Estradiol — the primary estrogen made by the ovaries.
Estrone — a weaker estrogen made by body fat.
Estrogen metabolites — breakdown products of estrogen, influenced by gut bacteria.
Ethinylestradiol — the potent synthetic estrogen found in most types of hormonal birth control.
Xenoestrogens — environmental estrogen-like chemicals from plastics, pesticides, and other endocrine disruptors.
Phytoestrogens — plant compounds that act weakly on estrogen receptors and usually have a beneficial, anti-estrogen effect. (See: Phytoestrogens are not estrogen.)

Causes of high estrogen

1) Hormonal birth control

The synthetic estrogen in birth control pills (ethinylestradiol) is four times stronger than your body’s own estradiol. It can impair estrogen detoxification and disrupt the gut microbiome.

2) Impaired estrogen metabolism

All estrogens must be detoxified in a two-step process through the liver and bowel.

Step 1 happens in the liver and requires B vitamins, selenium, and the amino acid glycine. It can be slowed by xenoestrogens and alcohol, which is one way alcohol can increase the risk of breast cancer.

Step 2 happens in the gut, where healthy bacteria are needed to help excrete conjugated estrogens. If the microbiome is disrupted, an enzyme called beta-glucuronidase can reactivate estrogen and send it back into circulation via enterohepatic recirculation or “gut-liver recirculation.”

3) Perimenopause

Estradiol increases during the early years of perimenopause, spiking up to three times higher than when you were younger. See: What estrogen does in your 40s and my perimenopause book, Hormone Repair Manual.

💡 Tip: At its peak, estradiol should not typically exceed 270 pg/mL (1000 pmol/L).

4) Insulin resistance

Insulin resistance increases the production of estrone from body fat, which is associated with PCOS, menopause, heart disease, and an increased risk of uterine cancer. See my book about insulin resistance.

5) Histamine and mast cell activation

Estrogen stimulates mast cells to release histamine and reduces the DAO enzyme needed to clear histamine. The result is more histamine, which can, in turn, stimulate more estrogen, creating a vicious cycle:

estrogen → histamine → estrogen → histamine.

For many women, symptoms of “estrogen dominance” such as PMS, period pain, and heavy periods improve by reducing histamine by avoiding cow’s dairy and other strategies. Read: The curious link between histamine intolerance and estrogen.

6) Estrogen receptor hypersensitivity

It’s not just how much estrogen you have—it’s also how sensitive your body is to it. You may be more sensitive if you have:

chronic inflammation
high histamine
iodine deficiency (Read: Why I prescribe iodine for PMS, breast pain, and ovarian cysts)

You can reduce estrogen sensitivity with beneficial phytoestrogens from legumes, nuts, and vegetables.

💡 Teenagers are naturally more sensitive to estrogen, which can explain their tendency toward heavy periods.

What is estrogen dominance?

The term “estrogen dominance” usually refers to high estrogen, but it can also describe normal estrogen combined with low progesterone.

See: Why I don’t use the term estrogen dominance — where I explain why I prefer the more precise terms of estrogen excess and progesterone deficiency.

💡 Endometriosis is affected by estrogen, but it’s not caused by estrogen. Instead, it’s a disease of immune dysfunction.