By: Michael Lam, MD, MPH

a bowl of Beta-Sitosterol with roots showingBeta-sitosterol is plant sterol found in almost all plants. It is one of the main subcomponents of a group of plant sterols known as phytosterols. It is white in colour and waxy in nature. It has a chemical structure that is very similar to cholesterol. High levels of Beta-sitosterol are found in rice bran, wheat germ, corn oils, and soybeans.

The average American diet lacks this component in their diet. Their diet contains only 200 to 300 mg of beta-sitosterol per day, which is not adequate.

The benefits of Beta-Sitosterol are as follows:

Controlling Cholesterol

Beta-sitosterol has been known to reduce cholesterol levels over the last three decades. Its close chemical resemblance to cholesterol enables it to block the absorption of cholesterol by competitive inhibition. Although beta-sitosterol is not well absorbed by the body (5-10%), when consumed with cholesterol it effectively blocks cholesterol’s absorption, resulting in lower serum cholesterol levels. Beta-sitosterol has also been shown to improve lipoprotein (HDL, LDL) profiles.

Promoting Prostate Health

In preventing and treating prostrate problems like benign prostatic hyperplasia (BPH), herbs such as saw palmetto extract, Pygeum africanum, and stinging nettle and pumpkin seeds are recommended.

In Europe, herbal preparations were often considered prescription drugs for patients with BPH. Plant sterols actually improved prostate symptom scores and reduced urine volume and residual urine levels without reducing the size of the prostate. Beta-sitosterol was one of the major components in these herbal preparations. Researchers also cited that beta-sitosterol alone was an effective option in the treatment of BPH.

Anti-Cancer Effects

Beta-sitosterol acts against cancer. It is found to reduce the growth of human prostate and colon cancer cells. It also acts against lymphocytic leukemia.

It appears that diets high in vegetables and fruits prevent cancer to a certain degree. Soybeans are superb sources of protein that reduces the risk of cancer too. Beta-sitosterol is one of the key compounds in soybeans that suppress carcinogenosis.

Boosts Immunity

Beta-sitosterol may give a boost to competitive athletes who often suffer from immune suppression and reduced inflammatory response during their intense training periods and competitions.

A small pile of beans to show you how Beta-Sitosterol can be found in most plantsBeta-sitosterol had been shown not only to boost their immunity but also noted to enhance lymphocyte proliferation and NK-cell activity. This is particularly useful to people who are physically stressed, medically unwell or recovering from illness.

Normalizes Blood Sugar

Beta-sitosterol has been shown to normalize blood sugar and insulin levels in Type II diabetics by stimulating the release of insulin in the presence of non-stimulatory glucose concentrations, and inhibiting glucose-6-phosphatase.

In the liver, the enzyme glucose-6-phosphatase is the primary pathway for conversion of dietary carbohydrates to blood sugar. Glucose-6-phosphatase dephosphorylates glucose-6-phosphate to yield free D-glucose. Free D-glucose passes into the blood, thus elevating blood sugar levels.

Reducing the blood glucose levels by down-regulation of glucose-6-phosphatase helps delay diabetes caused by old age.

Other Benefits of Beta-sitosterol

Beta-sitosterol has the ability to relieve inflammation, heal ulcers, enhance uterine tone and alleviate cramps. It also has anti-viral, anti-bacterial and anti-fungal agents.

Because of all these properties, adequate Beta-sitosterol can be an important nutritional tool to combat the effects of stress on the body. Stress comes in many forms, whether emotional or physiological. One of the most prevalent sources of stress in today’s modern society comes from the diet. The overabundance of carbohydrates and sugars boosts the caloric content of the typical western diet to irresponsible levels. This creates extra work for your body’s metabolic components which can degrade their function over time.

The stress to and dysfunction of the body’s metabolism has further consequences for the body’s stress handling a capacity and health in general. The neuroendometabolic (NEM) stress response system mitigates the effects of stress on the body’s function. However, when one of the components of the NEM system is dysfunctional, such as metabolism, this degrades the ability of the body to deal with stress, which can lead to a variety of stress related symptoms from anxiety and irritability to heart palpitations and fatigue.


  1. 300 mg up to 5 grams per day for reduction of high blood cholesterol.
  2. Between 60 and 130 mg per day for prostatic hyperplasia-related symptoms.
  3. 300 mg supplement per day is recommended as dietary health supplements.


Beta-sitosterol is an effective option in the treatment of benign prostatic hypertrophy, lowering cholesterol, increase immunity and reduce inflammation.

Additional reading: Plant Sterol and the Prostate

A small pile of beans to show you how Beta-Sitosterol can be found in most plants
5 -
Dr. Lam,
I am following your advice after reading your literature. I have not had any sugar, grains, corn, gluten for almost 4 weeks and I am losing weight, exercising and I feel great! I eat lots of vegetables, only Granny Smith apples, berries, nuts, seeds brown rice, millet and minimal organic chicken or fish. I am drinking lots of water as well. I am also sleeping much better, skin clearer and chronic symptoms improving. Thanks for the 'tough love,' Dr. Lam, and telling me to 'get educated' on my issues. You're a blessing.


  • Caroline Heinemann says:

    If you test high in absorption of Beta Sitosterol (absorbed from food # is 337 and campesterol 330 – would a sterol and stanol products be helpful or harmful? Total cholesterol 155 and hdl only 35
    thanks so much

    • Dr.Lam says:

      Your total cholesterol of 155 is on the low end. remember your body need cholesterol for hormone production. Too low a total cholesterol is not good for your body, so you need to talk to your doctor first about the general goal and direction you are heading before embarking on any supplements. sterol products has their place, but usually as a complementary compound and not as primary for cholesterol control.

      Dr Lam

  • Ana says:

    can beta sitosterol bind to cholesterol and be able to detect cholesterol levels in the blood?

    Im making this as a thesis proposal in my school and hoping to get great marks =)

  • Ryan says:

    Hello Dr. Lam. I am pre-diabetic and am interested in using beta-sitosterol to regulate blood sugar. Can you describe how this works, and if it’s safe for pre-diabetes?

    • Dr. Lam says:

      For pre-diabetic, use diet control is best. stop all carbohydrates. that works and is much better for you.

      Dr Lam

  • Bruce says:

    Hi Dr. Lam. You mention most Americans receive only 200 – 300 mg of beta-sitosterol per day and that this isn’t adequate. The dosage recommendations are within this range though, with the exception of the use of reduction of high cholesterol. How much beta-sitosterol is safe?

    • Newsletter says:

      you do get some plant sterols in your food, so 200-300 mg for maintaining normal health is good enough in terms of supplementation . There is no established “safe” dose , but generally speaking, up to 3-4 times that amount is used to lower cholesterol and has been shown to be very safe over time.

      Dr Lam