Medically Reviewed by Jennifer Robinson, MD on March 17, 2023
3 min read

Beta-glucans are types of fiber found in the cells of certain types of yeast, algae, bacteria, and fungi.

They are also found in certain plants, such as oats and barley.

Beta-glucans made from yeast may help lower cholesterol. Studies have shown that they may slightly lower total cholesterol and LDL ("bad") cholesterol. However, they do not seem to affect HDL ("good") cholesterol and triglycerides.

Beta-glucans have been studied in people with certain types of cancer. For example, one study showed that combining a type of beta-glucans called lentinan with chemotherapy can help people with gastric cancer live longer. More research is needed to see how effective it might be.

Studies also show that beta-glucans may help people with cervical and head and neck cancers. They may also increase survival time in some people with advanced cancers. Again, more studies are needed.

Beta-glucans do not seem to directly kill cancer. However, scientists think they may help your immune system better fight tumors and bacteria.

Early evidence shows that the supplement's immune-boosting abilities may also be helpful to people with AIDS. It may also lower your risk for infections after surgery and trauma. Further studies will help show if these are true.

Supplement makers sometimes claim that the fiber in beta-glucans supplements can help you feel fuller. This might help you eat less, which could make you lose weight. But, there is not enough evidence to show that beta-glucans can cause weight loss.

Optimal doses of beta-glucans have not been set. Supplement ingredients and quality may vary widely from maker to maker. This makes it hard to set a standard dose.

Beta-glucans have been taken by mouth in studies looking at their effect on people with high cholesterol and diabetes. Research with people affected by HIV/AIDS or serious infections have used injectable forms of beta-glucans. It has also been tried topically on the skin in research in people with burns.

Beta-glucans are commonly found in:

  • Certain mushrooms 
  • Grains such as oats and barley 
  • Baker's yeast 

Soluble forms of beta-glucans made from yeast or fungi appear safe when taken by mouth. Side effects may include:

Sometimes, doctors prescribe beta-glucans to be given through an IV. Side effects may include:

It's not known if this supplement is safe for women who are pregnant or breastfeeding.

Some types of beta-glucans may not be safe to take if you have certain health conditions. Talk to your doctor before taking this supplement if you have:

  • AIDS or AIDS-related complex (ARC)
  • Diabetes
  • High blood pressure

Beta-glucans may interfere with some medicines. Talk to your doctor before taking this if you are taking any other medicines. Do not take beta-glucans if you take certain blood pressure medicines, drugs that suppress the immune system, or certain non-steroidal medicines unless instructed by your doctor

The U.S. Food and Drug Administration (FDA) does regulate dietary supplements; however, it treats them like foods rather than medications. Unlike drug manufacturers, the makers of supplements don’t have to show their products are safe or effective before selling them on the market.