Equol is a chemical that comes from soy. It has some effects that are similar to the hormone estrogen. It exists in two forms: R-equol and S-equol.

When soy is eaten, certain bacteria in the gut change the chemicals found in soy into equol. But this change only occurs in 20-60% of people. People who are able to convert the chemicals in soy into equol might get more health benefits from soy. These people are called equol producers. Equol supplements can be used as a source of equol for people who are not equol producers.

People use equol for symptoms of menopause. It is also used for aging skin, diabetes, osteoporosis, breast cancer, and many other conditions, but there is no good scientific evidence to support these other uses.
When taken by mouth: Equol is likely safe when used for up to one year. It can cause some mild side effects such as constipation and bloating.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if equol is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Breast Cancer: There isn't enough reliable information about the effects of equol in people with breast cancer, a history of breast cancer, or a family history of breast cancer. Speak with a healthcare professional before taking equol supplements.


NatMed Pro rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
  • Symptoms of menopause. Taking equol by mouth might improve symptoms related to menopause, including hot flashes.
There is interest in using equol for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
Insufficient evidence Effectiveness definitions

Dosing & administration

Equol has most often been used by adults at a dose of 10 mg by mouth daily for up to 1 year. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Interactions with pharmaceuticals

Birth control pills (Contraceptive drugs)

Interaction Rating=Moderate Be cautious with this combination.

Some birth control pills contain estrogen. Taking equol along with birth control pills might increase the risk of side effects from the birth control pills.


Interaction Rating=Moderate Be cautious with this combination.

Equol might increase the amount of free estrogen in the body. Taking equol along with estrogen might increase the risk of side effects from estrogen replacement therapy.


Interaction Rating=Moderate Be cautious with this combination.

Equol might increase the amount of free testosterone in the body. Taking equol along with testosterone might increase the risk of side effects from testosterone replacement therapy.

Water pills (Diuretic Drugs)

Interaction Rating=Minor Be watchful with this combination.

Equol can decrease potassium levels. "Water pills" can also decrease potassium levels. Taking equol along with "water pills" might make potassium levels drop too low.

Interactions with herbs & supplements

Soy: Some people are able to turn soy into equol in the stomach. In these people, taking equol with soy or soy isoflavones might increase the risk of side effects from equol.

Interactions with foods

Food can slow the absorption of equol. It is best to take it before meals.
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