PC SPES, the popular herbal supplement which was withdrawn from sale earlier this year after it was found to contain traces of blood thinner wafarin, also contained an oestrogen drug and a painkiller, according to new research.
A report in the Washington Post cites a study by Robert A. Nagourney presented at last week's annual meeting of the American Association for Cancer Research which claimed to have found traces of prostrate cancer drug DES and the arthritis treatment indomethacin, both of which had been missed by earlier tests.
"I do not for a moment belittle [past] efforts," the paper quoted Nagourney as saying, adding that the testing of the supplement had been difficult as it contained eight different herbs and many different compounds. Nagourney said he had recommended the supplement to his patients for years because it was highly effective.
BotanicLab, the company which makes PC SPES, has repeatedly stressed that the supplement did not contain DES, citing several earlier tests, including the one by the California Department of Health which discovered wafarin. It added that it was moving its production facilities to Shanghai, where it sources the herbs for PC SPES, and that it was stepping up its product control procedures.
BotanicLab has been carrying out its own investigation into whether the wafarin detected by the California health authorities was in fact synthetic - and therefore illegal in a herbal supplement - or in fact one of the natural compounds contained in the supplement which was simply mimicking the wafarin effect.