Genistein Combined Polysaccharide

Last Editorial Review: 6/11/2021
Other Name(s):

Basidiomycetes Polysaccharide, Fermented Genistein, Fermented Isoflavone, GCP, Genistein Polysaccharide, Génistéine du Polysaccharide Combiné, Génistéine Fermentée, Isoflavone Combined Polysaccharide, Isoflavone Fermentée, Polisacáridos Combinados de Genisteína, Polysaccharide de Génistéine, Polysaccharide des Basidiomycètes, Polysaccharide d'Isoflavone de Soja, Soy Isoflavone Polysaccharide.


Genistein combined polysaccharide is a chemical that is removed from specially processed (fermented) soy.

Genistein combined polysaccharide is used for prostate cancer and breast cancer.

How does work?

Genistein combined polysaccharide might work for some forms of cancer by decreasing certain hormones.


Insufficient Evidence to Rate Effectiveness for...

  • Prostate cancer. One patient with prostate cancer seemed to benefit from taking genistein combined polysaccharide for six weeks. His prostate became smaller and lab tests suggested improvement.
  • Breast cancer.
  • Other conditions.
More evidence is needed to rate the effectiveness of genistein combined polysaccharide for these uses.


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Side Effects

There isn't enough information to know if genistein combined polysaccharide is safe.


Pregnancy and breast-feeding: Not enough is known about the use of genistein combined polysaccharide during pregnancy and breast-feeding. Stay on the safe side and avoid use.

Hormone-sensitive condition such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Genistein combined polysaccharide might act like estrogen. If you have any condition that might be made worse by exposure to estrogen, don't use genistein combined polysaccharide.


The appropriate dose of genistein combined polysaccharide depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for genistein combined polysaccharide. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

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Barnes S, Kim H, Darley-Usmar V, et al. Beyond ERalpha and ERbeta: Estrogen receptor binding is only part of the isoflavone story. J Nutr 2000;130:656S-7S. View abstract.

Ghafar MA, Golliday E, Bingham J, et al. Regression of prostate cancer following administration of genistein combined polysaccharide (GCP), a nutritional supplement: A case report. J Altern Complement Med 2002;8:493-7. View abstract.

Yuan L, Wagatsuma C, Yoshida M, et al. Inhibition of human breast cancer growth by GCPTM (genistein combined polysaccharide) in xenogeneic athymic mice: involvement of genistein biotransformation by beta-glucuronidase from tumor tissues. Mutation Res 2003;523-524:55-62. View abstract.