Holistic Health Supplements Health Benefits of Beta-Sitosterol Plant-based compound may reduce your risk of heart disease By Cathy Wong Cathy Wong Facebook Twitter Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health. Learn about our editorial process Updated on September 06, 2021 Medically reviewed by Emily Dashiell, ND Medically reviewed by Emily Dashiell, ND on July 29, 2020 Facebook LinkedIn Emily Dashiell, ND, is a licensed naturopathic doctor who has worked in group and private practice settings over the last 15 years. She is in private practice in Santa Monica, California. Learn about our Medical Review Board Print Verywell / Anastasia Tretiak Table of Contents View All Table of Contents Health Benefits Possible Side Effects Dosage and Preparation What to Look For Other Questions Beta-sitosterol is one of several plant-based substances known as phytosterols. Phytosterols are similar in structure to cholesterol and may help reduce the risk of heart disease if consumed in ample quantities. The richest source sources of phytosterols are vegetable oils and the products made from them. Nuts, seeds, and legumes also contain phytosterols. In addition to food sources, beta-sitosterol is sold in supplement form to treat high cholesterol and a host of other disorders. Despite its ability to lower "bad" low-density lipoprotein (LDL) cholesterol, there is only limited evidence that it can prevent or treat specific medical conditions. Health Benefits Alternative practitioners believe that beta-sitosterol can treat diseases as far-ranging as allergy, asthma, chronic fatigue syndrome, fibromyalgia, gallstones, migraine, psoriasis, rheumatoid arthritis, and menstrual disorders. In addition, beta-sitosterol is purported to prevent heart disease and certain forms of cancer (including prostate cancer and colon cancer). Despite considerable gaps in clinical research, a number of smaller studies have hinted at potential benefits of beta-sitosterol use. Cardiovascular Disease Beta-sitosterol may reduce the risk of cardiovascular disease (CVD) by lowering LDL cholesterol in the blood. By increasing your dietary intake, beta-sitosterol effectively competes with animal cholesterol for absorption in the intestines. Over time, this can reduce the risk of atherosclerosis (hardening of the arteries), a condition which contributes to heart attack and stroke. Research has consistently shown that eating 2 grams of phytosterols per day can reduce your LDL cholesterol by anywhere from 8 to 10 percent. Anything less than 1.3 grams per day of phytosterols does not confer to a reduction in CVD risk, according to 2019 guidance from the U.S. Food and Drug Administration (FDA). Moreover, while beta-sitosterol supplements may contribute to a reduced CVD risk, there are no indications that the supplements can do so without other interventions, such as a reduced-fat diet and routine exercise. Benign Prostatic Hyperplasia Beta-sitosterol may aid in the treatment of an enlarged bladder, also known as benign prostatic hyperplasia or BPH. Higher doses were not able to improve upon these results. While beta-sitosterol cannot directly treat BPH, it may be used in complement with traditional drugs for men with decreased urinary flow and urinary hesistancy. Cancer Beta-sitosterol supplements are often promoted for their anti-cancer properties. Most of the evidence supporting these claims are based on test tube studies. According to a 2010 trial published in BMC Complementary and Alternative Medicine, beta-sitosterol isolated from tropical milkweed (Asclepias curassavica) inhibited the growth of human colon cancer cells. Similarly, a 2003 study 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 spread of cancer cells. A 2008 study published in Molecular Nutrition and Food Research found that using beta-sitosterol in combination with the breast cancer drug tamoxifen appeared to enhance the drug's effectiveness against breast cancer cells. None of this should suggest that beta-sitosterol has any direct impact on cancer cells. Rather, it hints at a possible avenue for cancer drug development in the future. Possible Side Effects Beta-sitosterol is considered safe when used at the recommended doses for up to six months. Side effects may include nausea, indigestion, bloating, diarrhea, and constipation. Less commonly, beta-sitosterol has been linked to erectile dysfunction and low libido. Beta-sitosterol should not be used in people with a rare genetic disorder known as sitosterolemia in which beta-sitosterol and other fats accumulate abnormally in the blood. Taking a beta-sitosterol supplement under such conditions may actually increase the risk of a heart attack. Beta-sitosterol may interact with Pravachol (pravastatin) and Zetia (ezetimibe), both of which are used to lower blood cholesterol levels. Taking either these drugs can reduce the effectiveness of beta-sitosterol. Due to the lack of safety research, beta-sitosterol should not be used in children, pregnant women, or nursing mothers. To avoid unforeseen side effects or interactions, speak with your doctor before taking a beta-sitosterol supplement. Verywell / Anastasia Tretiak Dosage and Preparation There are no universal guidelines directing the appropriate use of beta-sitosterol supplements. The supplements are typically found in capsule, tablet, or soft gel form in doses ranging from 60 to 500 milligrams (mg). Dosages of 800 mg or more per day, divided and taken before meals, have been used safely in people with high cholesterol. By contrast, a dose of no more than 130 mg per day may be enough to promote urination in men with BPH. Widely available for purchase online, beta-sitosterol supplements are sold in many natural food shops and in stores specializing in dietary supplements. What to Look For Dietary supplements are largely unregulated in the United States. As a result, the contents and/or concentration of active ingredients may differ from one brand to the next. To better ensure safety and quality, opt for supplements that have been tested and certified by an independent certifying body like the U.S. Pharmacopeia (USP), ConsumerLab, or NSF International. Beta-sitosterol supplements are stable at room temperature but can degrade quickly if exposed to excessive heat or UV radiation. Always store your supplements in their original light-sensitive container, ideally in a cool, dry room. Other Questions Do I need a beta-sisoterol supplement? Generally speaking, it is always best to get your micronutrients from food rather than supplements. Among some of the foods especially rich in beta-sitosterol are: Canola oil: 96 mg per tablespoonAvocados: 95 mg per cupPistachio nuts (raw): 71 mg per cupAlmonds (raw): 46 mg per cupFava beans (fresh): 41 mg per cupSoybean oil: 39 mg per tablespoonHazelnuts: 34 mg per cupWalnuts: 33 mg per cupPink lentils: 27 mg per cup On the other hand, if you are unable to control your cholesterol despite the appropriate interventions (such as diet and exercise), speak with your doctor to see if a beta-sitosterol supplement may help. If your cholesterol levels are borderline for treatment, it may be worth a try. However, if your cholesterol is consistently elevated, your doctor may want to start you on statin drugs rather than a dietary supplement. Best Food Sources for Phytosterols Frequently Asked Questions Are beta-sitosterol supplements safe for benign prostatic hyperplasia? They seem safe for most men who take them for BPH. For some people, though, they may cause an upset stomach. You should check with your doctor first to be sure that the symptoms you have are not related to a different condition that needs other treatment. Learn More: What You Should Know About Prostate Cancer Symptoms Can taking beta-sitosterol raise testosterone levels? There is some research showing that testosterone levels rose in men who took saw palmetto enriched with beta-sitosterol compared to a control group, but there's still limited information on the connection, and more studies are needed. Learn More: Why Testosterone Is Important Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Oregon State University. Phytosterols. Racette SB, Lin X, Lefevre M, et al. Dose effects of dietary phytosterols on cholesterol metabolism: a controlled feeding study. Am J Clin Nutr. 2010;91(1):32-8. U.S. Food and Drug Administration. CFR - Code of Federal Regulations Title 21. Updated April 1, 2019. Kaiser Permanente. Beta-sitosterol uses. Updated May 28, 2015. 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;10:24. 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;10(2):497–500. Consumer Reports. Heart supplements: proceed with caution. Updated February 2011. Genetics Home Reference. Sitosterolemia. Updated January 21, 2020. Akabas SR, Vannice G, Atwater JB, Cooperman T, Cotter R, Thomas L. Quality certification programs for dietary supplements. J Acad Nutr Diet. 2016;116(9):1370-1379. doi:10.1016/j.jand.2015.11.003 Self Nutrition Data. Foods highest in beta-sitosterol. University of Michigan Health. Beta-Sitosterol Plant Extract. Updated September 23, 2020. Sudeep HV, Thomas JV, Shyamprasad K. A double blind, placebo-controlled randomized comparative study on the efficacy of phytosterol-enriched and conventional saw palmetto oil in mitigating benign prostate hyperplasia and androgen deficiency. BMC Urol. doi:10.1186/s12894-020-00648-9 Additional Reading AbuMweis, S.; Marinangeli, C.; Frohlich, J. et al. Implementing phytosterols into medical practice as a cholesterol-lowering strategy: overview of efficacy, effectiveness and safety. Can J Cardiol. 2014; 30:1225-32. DOI: 10.1016/j.cjca.2014.04.022. Awad AB, Barta SL, Fink CS, and 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. Wilt TJ, MacDonald R, and Ishani A. Beta-sitosterol for the treatment of benign prostatic hyperplasia: a systematic review. BJU Int. 1999 Jun;83(9):976-83.