What to Know About Soy Protein Isolate

Reviewed by Dan Brennan, MD on November 08, 2021

If you’re looking for a protein supplement to add to your diet, soy protein isolate is a popular option that has many health benefits.

What Is Soy Protein Isolate?

Soy protein isolate is a protein that comes from soybeans. It’s cheaper than some protein options and easy to add to your diet.

You can use soy protein to help you lose weight, boost energy, or build muscle. Soy protein isolate may also manage your hormone balance and lower your risk of breast cancer, heart disease, and osteoporosis

Protein is important for your overall health and boosts development. Soy protein is 90% protein. Other plant proteins don't have the complete nutritional value that soy does. You may need to add vitamins and minerals to those plant proteins that can already be found in soy protein. 

Studies have shown that soy protein can also help your gut barrier, making it easier for your body nutrients. The researchers say dietary soy protein helps your immune defense, too. 

Benefits of Soy Protein Isolate

Soy is a complete protein with all nine essential amino acids, more than other plant proteins. It has lots of health benefits: 

Cholesterol. Soy protein is good for lowering cholesterol levels, low-density lipoproteins (LDL or “bad” cholesterol), and triglycerides. There’s no cholesterol in soy protein isolate. 

Protein. If you’re on a vegetarian or vegan diet, soy protein is a healthy way to reach your protein goals.  

Cardiovascular health. Eating soy protein isolate instead of animal proteins can help improve your overall heart health. Soy protein isolate supplements are meant to make you feel full. 

Gastrointestinal health. Soy protein has fiber, which is great for your gastrointestinal system. Adding fiber to your diet keeps your stomach and lower intestines healthy. 

Vitamins and minerals. Soy foods are high in vitamins and minerals including B vitamins, zinc, and iron. Some supplements have calcium and vitamin D in them, too. There are also plenty of antioxidants in soy. 

Isoflavones. Some studies have linked isoflavones, chemicals that can be found in soy protein, to prevention of bone loss that may happen after menopause and with certain cancers. 

Where Is Soy Protein Isolate Found?

Soy protein is a common isolate that’s easy to dissolve. It’s used as a supplement or as an ingredient in food. Supplemental protein powder is often mixed with vitamins, minerals, and flavoring. 

You may find soy protein isolate in things like soy flour or grits that are used for breakfast cereal, processed meats, and baby foods. 

Show Sources


Advances in Experimental Medicine and Biology: “Soy protein utilization in food systems.”

American Family Physician: “Soy: A Complete Source of Protein.”

Cleveland Clinic: “Soy Foods.”

Harvard T. H. Chan School of Public Health: “Straight Talk About Soy.”

International Journal of Current Research and Review: “Protein Isolates: Production, Functional Properties and Application.”

Journal of Agricultural and Food Chemistry: “Soy Protein Isolate Components and Their Interactions.”

The Journal of Nutrition: “Soy protein products: processing and use.”

The Journal of Perinatal Education: “Soy Protein.”

National Cancer Institute: “soy protein isolate.”

Nutrients: “Dietary Soy Protein Isolate Attenuates Intestinal Immunoglobulin and Mucin Expression in Young Mice Compared with Casein.”

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