Background

Beta-sitosterol is a type of chemical called a plant sterol. It's similar to cholesterol and is found in fruits, vegetables, nuts, and seeds.

Beta-sitosterol might help reduce cholesterol levels by limiting the amount of cholesterol that is able to enter the body. It can also help reduce swelling in the prostate and other tissues.

People most commonly use beta-sitosterol for lowering cholesterol levels and improving symptoms of an enlarged prostate (BPH). It's also used for heart disease, rheumatoid arthritis (RA), male-pattern baldness, and many other conditions, but there is no good scientific evidence to support many of these other uses.

In the US, foods that contain at least 650 mg of beta-sitosterol are allowed to state that they might reduce the risk for heart disease. Don't confuse beta-sitosterol with sitostanol, a similar plant substance.

Safety Safety definitions

When taken by mouth: Beta-sitosterol is likely safe for most people. It's been used safely at a dose of up to 20 grams daily for up to 3 months. It's also been used at a lower dose of 130 mg daily for up to 18 months. It can cause some mild side effects, such as nausea, indigestion, gas, diarrhea, or constipation.

When applied to the skin: There isn't enough reliable information to know if beta-sitosterol is safe or what the side effects might be.

Special Precautions & Warnings:

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

Children: Beta-sitosterol is likely safe when taken in doses of up to 12 grams daily (divided into 3 separate doses) for up to 3 months.

Sitosterolemia, a rare inherited fat storage disease: People with this condition have too much beta-sitosterol and related fats in their blood and tissues. Taking beta-sitosterol makes this condition worse. Don't take beta-sitosterol if you have sitosterolemia.

Effectiveness

Dosing & administration

In adults, beta-sitosterol has most often been used in doses of 3-4 grams by mouth daily for up to 3 months. It's also been used at a lower dose of 60-130 mg daily for up to 18 months. In children, beta-sitosterol has most often been used in doses of 6-12 grams by mouth daily for up to 3 months. Beta-sitosterol is also available in ointments. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.

Interactions with pharmaceuticals

It is not known if Beta-Sitosterol interacts with any medicines. Before taking Beta-Sitosterol, talk with your healthcare professional if you take any medications.

Interactions with herbs & supplements

Carotenoids: Beta-sitosterol can reduce how much carotenoids the body absorbs. This includes chemicals like alpha-carotene, beta-carotene, lutein, lycopene, and zeaxanthin. But this may not be important to health. Taking extra carotenoids is probably not necessary.
Vitamin E: Beta-sitosterol may reduce how much vitamin E the body absorbs. But this may not be important to health. Taking extra vitamin E is probably not necessary.

Interactions with foods

Beta-sitosterol might reduce how much carotene and vitamin E the body absorbs from foods. But this doesn't seem to be a major concern, so taking supplemental amounts of these nutrients probably isn't necessary.