Reviewed on 9/20/2021

What Is Phytoestrogens Used For and How Does it Work?

Phytoestrogens are used to treat menopausal vasomotor symptoms and osteoporosis, and to decrease the risk of breast cancer and cardiovascular disease.

  • Studies show reasonable efficacy of phytoestrogens for breast cancer, diabetes, osteoporosis prevention/treatment, hot flashes, and cardiovascular disease risk.
  • There are mixed results with use of phytoestrogens for cancer prevention.
  • Phytoestrogens are available under the following different brand and other names: isoflavones, daidzein, genistein, ipriflavone, ostivone, and soy isoflavones.

What Are Dosages of Phytoestrogens?

Dosages of Phytoestrogens:


Dosage Considerations – Should be Given as Follows:


  • 40 mg orally once daily
  • Menopausal symptoms: 34-120 mg/day
  • Hypertension: 18 mg orally twice daily
  • Lung cancer prevention: 8.3-83.2 mcg/day


  • 200 mg orally three times daily

CrCl 40-80 mL/min

  • 200 mg orally twice daily

CrCl less than 40 mL/min

  • 200 mg orally once daily


If menopause occurs in a woman younger than ___ years, it is considered to be premature. See Answer

What Are Side Effects Associated with Using Phytoestrogens?

Side effects of Phytoestrogens include:

  • Allergic reaction

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Phytoestrogens?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Phytoestrogens?


  • This medication contains phytoestrogens. Do not take isoflavones, daidzein, genistein, ipriflavone, ostivone, or soy isoflavones if you are allergic to phytoestrogens or any ingredients contained in this drug.
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Pregnancy

Effects of Drug Abuse

No information is available.

Short-Term Effects

  • See "What Are Side Effects Associated with Using Phytoestrogens?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Phytoestrogens?"


  • No information is available.

Pregnancy and Lactation

  • Avoid the use of phytoestrogens during pregnancy. No information is available about the use of phytoestrogens during lactation. Consult your doctor before breastfeeding.


What Is Osteoporosis? Treatment, Symptoms, Medication See Slideshow
Medscape. Phytoestrogens.

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