PSK: A Non-Toxic Polysaccharide Drug

If you’re from Japan, you’re probably wondering why I’ve listed PSK under alternative therapies. In Japan, PSK is an approved anti-cancer drug with 20 years of research behind it. PSK sales in Japan account for hundreds of millions dollars worth of sales each year. But in the US, PSK is little known, is not used by mainstream doctors, and until recently nothing like it was readily available. Now a nutritional supplement designed to be identical to PSK is available in the US, but very few mainstream doctors, and actually not many alternative practitioners are aware of it. So in the US, PSK has the status of a little known nutritional supplement or alternative therapy. Which is too bad in light of its proven benefits, easy administration, and lack of toxicity. Before I start sounding too much more like an advertisement, let me confess. I really am excited about it, but I have no financial interest in it; I’m not selling it.

PSK doesn’t have the hype associated with many alternative therapies, but it does have one thing most alternative therapies don’t. Extensive documented results published in mainstream medical journals. Of all of the so called alternative therapies, this is one I can positively endorse – because of the great depth of published medical research supporting its use in cancer treatment.

Like many of the more interesting non-toxic anti-cancer agents, such as Lentinan, and Bovine Cartilage, PSK is a polysaccharide complex with immune stimulating effects. Polysaccharides are large molecules made up of chains of linked sugar molecules. PSK is actually a polysaccharide-protein complex. PSK, like Lentinan, is derived from a fungus, in this case Coriolus Versicolor, which is a common edible mushroom. A Western common name is “Turkey Tail”.

Both PSK and Lentinan (Derived from the Shitake mushroom) have demonstrated benefit in colon and cancer patients in controlled clinical trials, however PSK has the great advantage that it has been administered orally in most if not all, human studies, while Lentinan has normally been administered by injection. This means that the proven benefits of PSK could be available by using it as a nutritional supplement. A common problem with nutritional supplements is that many, such as most enzyme preparations, as well other protein based supplements, are not absorbed when taken orally. You always have to consider whether oral administration of a supplement is going to be effective. In this case, it’s no problem.

The depth of published research for PSK as an anti-cancer agent is extremely impressive compared to any other alternative therapy I have ever come across. In addition to multiple animal studies documenting a multitude of immune boosting effects and anti-tumor effects, this drug has nearly 20 years of research with humans behind it. This research does not show that PSK is the most powerful non-toxic treatment known. In fact, PSK does not appear to be anything like a “miracle cure”. Mostly it has shown modest to moderate benefit when used as adjuvant therapy, usually in combination with chemotherapy using 5-FU or related agents. But consider that these benefits, which can include 20 absolute percentage point advantages in five year survival in certain situations, come in a therapeutic sense, for free. That’s because PSK is virtually non-toxic with almost no side effects reported. In this situation – well documented benefits, and no toxic downside, there’s nothing to lose and everything to gain. If I had one of the cancers in which this has shown benefit I would not hesitate to use PSK. Of course, I would not use PSK in place of conventional therapy. That could be a fatal mistake. I would use PSK with conventional therapy. Indeed, all of the best clinical results with PSK are in conjunction with standard therapy.

Some of the more impressive human clinical results include:

  • Stomach Cancer: A randomized study of 262 patients with completely resected stomach cancer showed that addition of PSK to standard adjuvant chemotherapy increased 5 year disease free survival from 59% to 70%. The results were statistically significant. This study was published in The Lancet, one of the most prestigious medical journals in the world.
  • Colorectal Cancer: Two different randomized studies showed statistically significant increases in survival when PSK was added to standard chemotherapy after complete resection of primary tumors. One of these studies had more than 200 patients in both the treatment and control groups.
  • Non Small Cell Lung Cancer: One randomized study of PSK as an adjuvant to radiotherapy showed an increase in 5 year survival from 16% to 39% in stage I and II disease and from 5 to 16% in stage III disease. Another study of PSK as an adjuvant to chemotherapy showed an increase in the response rate in stage III disease, with a modest improvement in survival, but no benefit in stage IV disease.

References for all of these studies are included in my MedLine search.

[MedLine Search on PSK]

A Coriolus Versicolor extract is now available as a nutritional supplement from a tiny company called JHS Natural Products. This product is designed to be exactly the same as PSK. As far as I know, it is as close to PSK as it is possible to get in the US.

Contact Information for JHS Natural Products
JHS Natural Products
P.O. Box 50398
Eugene, Ore 97405
(888) 330-4691
(541) 344-1396

The JHS Natural Products Web Page is quite informative and offers information on how to obtain their Coriolus Vericolor Supplement.

This CancerGuide Page By Steve Dunn. © Steve Dunn
Page Created: 1996, Last Updated: Apr 27, 2000