The Benefits of Beta-Sitosterol

What You Need to Know

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Beta-sitosterol is a substance found naturally in a number of foods, including soy, flaxseed, peanuts, olive oil, and many fruits and vegetables. Also available in dietary supplement form, beta-sitosterol is classified as a phytosterol (a class of compounds similar to cholesterol). Some scientific studies suggest that beta-sitosterol may offer certain health benefits.


Beta-sitosterol is touted as a natural remedy for a variety of health conditions, including:

In addition, beta-sitosterol is purported to prevent heart disease and some forms of cancer (including prostate cancer and colon cancer). Proponents also suggest that beta-sitosterol can help stimulate the immune system, relieve pain, reduce inflammation, and enhance sexual function.


Here's a look at the science behind the potential health benefits of beta-sitosterol:

1) Benign Prostatic Hyperplasia

There's some evidence that beta-sitosterol may help treat benign prostatic hyperplasia (or BPH, a condition commonly referred to as "enlarged prostate"). Although BPH rarely causes symptoms in men under age 40, many older men experience BPH-related symptoms (including urination and bladder problems). BPH is not linked to increased risk for prostate cancer.

Beta-sitosterol appears to improve urological symptoms associated with BPH, according to a report published in BJU International in 1999. For the report, investigators analyzed four previously published clinical trials with a total of 519 men and a treatment period of four to 26 weeks. Although the report's authors concluded that short-term treatment with beta-sitosterol may help improve BPH symptoms, they caution that beta-sitosterol's effectiveness as a long-term BPH treatment is unknown.

There is a lack of more recent research on the effectiveness of beta-sitosterol in the treatment of BPH.

2) Cancer

In a 2010 laboratory study published in BMC Complementary and Alternative Medicine, for instance, scientists found that beta-sitosterol isolated from the Asclepias curassavica plant inhibited the growth of human colon cancer cells.

Some research indicates that beta-sitosterol may also fight breast cancer. For example, a 2003 laboratory study published in Oncology Reports found that beta-sitosterol induced apoptosis in breast cancer cells. Apoptosis, a type of programmed cell death, is key to halting the proliferation of cancer cells.

Furthermore, a 2008 laboratory study published in Molecular Nutrition and Food Research found that using beta-sitosterol in combination with the breast cancer drug tamoxifen may enhance the drug's effectiveness.

It's important to note that more research needs to be conducted before beta-sitosterol can be recommended for the treatment or prevention of any form of cancer.


Beta-sitosterol is generally considered safe when consumed in recommended doses for up to six months. However, there's some concern that beta-sitosterol may contribute to harmful effects in people with certain chronic conditions (including diabetes, gallstones, and Alzheimer's disease). Therefore, it's critical to talk to your physician prior to using beta-sitosterol supplements.

Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label.

Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. 

Where to Find It

Widely available for purchase online, beta-sitosterol supplements are sold in many natural-food stores and in stores specializing in dietary supplements.

Using Beta-Sitosterol for Health

Due to a lack of supporting research, beta-sitosterol cannot currently be recommended for treatment or prevention of any health problem. If you're considering the use of beta-sitosterol supplements, consult your doctor before starting your supplement regimen.

It's important to note that self-treating a chronic condition with beta-sitosterol and avoiding or delaying standard care may have serious health consequences.

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Article Sources
  • Awad AB, Barta SL, Fink CS, Bradford PG. "beta-Sitosterol enhances tamoxifen effectiveness on breast cancer cells by affecting ceramide metabolism." Mol Nutr Food Res. 2008 Apr;52(4):419-26.
  • Awad AB, Chen YC, Fink CS, Hennessey T. "beta-Sitosterol inhibits HT-29 human colon cancer cell growth and alters membrane lipids." Anticancer Res. 1996 Sep-Oct;16(5A):2797-804.
  • Awad AB, Roy R, Fink CS. "Beta-sitosterol, a plant sterol, induces apoptosis and activates key caspases in MDA-MB-231 human breast cancer cells." Oncol Rep. 2003 Mar-Apr;10(2):497-500.
  • Baskar AA, Ignacimuthu S, Paulraj GM, Al Numair KS. "Chemopreventive potential of beta-Sitosterol in experimental colon cancer model--an in vitro and In vivo study." BMC Complement Altern Med. 2010 Jun 4;10:24.
  • Wilt TJ, MacDonald R, Ishani A. "beta-sitosterol for the treatment of benign prostatic hyperplasia: a systematic review." BJU Int. 1999 Jun;83(9):976-83.