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 from the ovaries.
- Estrone from body fat.
- Estrogen metabolites from intestinal bacteria.
- Ethinylestradiol from oral contraceptives.
- Xenoestrogens from endocrine-disrupting chemicals (EDCs).
- Phytoestrogens from plants. Phytoestrogens act so weakly on estrogen receptors that they generally have a beneficial anti-estrogen effect. Read Phytoestrogens are not estrogen.
Causes of high estrogen
1) Hormonal birth control
The estrogen ethinylestradiol is stronger than estradiol, so it is a big dose of estrogen. It can also damage the gut microbiome and impair estrogen metabolism.
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. This step of estrogen metabolism can be impaired by xenoestrogens and alcohol, which is why alcohol causes higher blood levels of estrogen and can increase the risk of breast cancer.
Step 2 happens in the bowel, where conjugated estrogens are escorted out of the body. In the presence of healthy gut bacteria, conjugated estrogens leave the body. In the presence of unhealthy bacteria, conjugated estrogens are de-conjugated and reactivated by the enzyme beta-glucuronidase. Reactivated estrogens can then be reabsorbed via enterohepatic recirculation or “gut-liver recirculation.” The result is estrogen excess.
Estradiol temporarily increases during the years before menopause, sometimes 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 highest point, your estradiol blood level should generally not exceed 270 pg/mL (1000 pmol/L).
4) Insulin resistance
Insulin resistance can promote too much estrone, which can be a problem with polycystic ovary syndrome (PCOS) and after menopause. Too much estrone post-menopause can increase the risk of uterine cancer.
5) Histamine and mast cell activation
Estrogen stimulates mast cells to make more histamine and down-regulates the DAO enzyme you need to clear histamine. The result is more histamine, which, unfortunately, then stimulates the ovaries to make more estrogen. The net result is a vicious cycle of:
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
Your actual amount of estrogen is only part of the story. It also matters how sensitive you are to it.
For example, you’ll be more sensitive to estrogen (and not in a good way) if you have chronic inflammation or high histamine or are deficient in iodine. Read Why I prescribe iodine for PMS, breast pain, and ovarian cysts.
You’ll be less sensitive to estrogen if you consume beneficial phytoestrogens from legumes, nuts, and vegetables.
👉 Teenagers are more sensitive to estrogen, so they can experience heavy periods.
What is estrogen dominance?
Estrogen dominance usually means too much estrogen, but it can also describe a situation of normal estrogen and too little progesterone.
I don’t use the term “estrogen dominance” because I prefer the more precise terms estrogen excess and progesterone deficiency. Read Why I don’t use the term estrogen dominance.
👉 Endometriosis is affected by estrogen, but it’s not caused by estrogen. Instead, it’s a disease of immune dysfunction.
How to lower estrogen
- Don’t take the combined contraceptive pill.
- Reduce alcohol to promote healthy estrogen metabolism.
- Eat vegetables for their beneficial phytoestrogen content.
- Identify and reverse insulin resistance to reduce the production of estrone.
- Reduce exposure to xenoestrogens such as plastics and pesticides.
- Avoid inflammatory foods such as dairy to reduce histamine and hypersensitivity to estrogen.
Best supplements to lower estrogen
- Calcium d-glucarate promotes healthy estrogen metabolism by inhibiting the bacterial enzyme beta-glucuronidase thereby reducing enterohepatic recirculation or the “gut-liver recirculation” of estrogen.
- Iodine down-regulates estrogen receptors, thereby decreasing estrogen sensitivity. Iodine is particularly helpful for breast symptoms such as tenderness or breast cysts. Iodine is generally safe up to 500 mcg (0.5 mg) and, although higher dose iodine can harm the thyroid, it’s usually safe if you test negative for thyroid antibodies.
- Progesterone can counterbalance estrogen, lighten periods, and improve breast tenderness and premenstrual mood. The progestins of hormonal birth control are not progesterone. Read The crucial difference between progestins and progesterone.