PC-SPES was, ostensibly, a formulation of eight natural products (seven herbs and one mushroom): Isatis indigotica, Glycyrrhiza glabra ( licorice), Panax pseudo-ginseng, Ganoderma lucidium ( reishi mushroom), Scutellaria baicalensis, Dendranthema morifolium, Robdosia rubescens, and Serenoa repens ( saw palmetto).

The name PC-SPES was derived from the common abbreviation for prostate cancer (PC) and the Latin word spes meaning hope. After its commercial launch in 1996, PC-SPES received considerable interest from the general public and reputable medical researchers as a treatment for prostate cancer. Unfortunately, it turned out to be a fraud.

PC-SPES was not truly a purely herbal product; samples dating back to 1996 were found to contain a form of pharmaceutical estrogen, diethylstilbestrol (DES), as well as indomethacin (an anti-inflammatory medication in the ibuprofen family) and warfarin (a strong blood thinner).19 Samples subsequent to 1999 contained less DES; but they also showed less effectiveness in treating prostate cancer.

There is little doubt that DES is active against prostate cancer, but it presents a variety of risks, including blood clots in the legs. The other two pharmaceutical contaminants might actually reduce this risk (which may be why they were covertly added), but present various risks all on their own. For these reasons, we strongly recommend against using PC-SPES at all.

The only proposed use of PC-SPES was the treatment of prostate cancer. The formulation was tried at various stages of the disease, and preliminary research indicated that it had potential, particularly for treating prostate cancer that is no longer responsive to hormone therapies. Benefits were reported in the two main types of prostate cancer: hormone-sensitive and hormone-insensitive cancer. However, when the covert addition of pharmaceuticals was discovered, interest in this "herbal" combination ended.