{"entity":{"id":"pc-spes","kind":"technology","name":"PC-SPES","aka":["PC SPES","Prostate-Res"],"tldr":"PC-SPES was an eight-herb mixture sold for prostate cancer that lowered PSA in men, but batches turned out to contain prescription drugs, including a synthetic oestrogen and a blood thinner. It was recalled in 2002 and is no longer made; products sold as substitutes are not the same thing.","summary":"PC-SPES combined reishi, Baikal skullcap, Isodon rubescens, isatis (dyer's woad), chrysanthemum, saw palmetto, Panax ginseng and licorice. Laboratory studies suggested activity against both hormone-sensitive and hormone-insensitive prostate cancer cells, and early human studies documented marked falls in PSA and testosterone. Memorial Sloan Kettering's About Herbs page records that contamination with diethylstilbestrol (a synthetic oestrogen), warfarin and alprazolam led the manufacturer to recall the product voluntarily in 2002. The NCI PDQ summary concludes that it is not known whether the effects in people came from the adulterants, the herbs, or both; the manufacturer is no longer in operation. Reported harms were those expected of oestrogen therapy: breast tenderness and enlargement, loss of libido and sexual function, and, less often, deep vein thrombosis, pulmonary embolism and oedema; one man bled into the abdomen after a month of unsupervised use. Products marketed as replacements are different formulations and few have been studied. The episode shows how a herbal product can appear to work because it contains a hidden drug.","status":"negative","asOf":"2026-11-04","links":[{"label":"MSK About Herbs: PC-SPES (page last updated 26 February 2021)","url":"https://www.mskcc.org/cancer-care/integrative-medicine/herbs/pc-spes"},{"label":"NCI PDQ: PC-SPES","url":"https://www.cancer.gov/about-cancer/treatment/cam/hp/pc-spes-pdq"}],"tags":["complementary","supportive-care","evidence:harm"],"related":["selenium-supplements","lycopene"],"cancers":["prostate"],"sections":["supportive-care","hormonal"],"technologies":["androgen-deprivation","traditional-chinese-herbal-medicine","alternative-medicine-instead-of-treatment"],"targets":[],"drugs":["diethylstilbestrol"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-misinformation"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"PSA and testosterone fell as they do with oestrogen therapy; because batches contained diethylstilbestrol, the herbal contribution could not be separated from the drug's.","strengths":["Showed that PSA response to a supplement can be measured in trials"],"limitations":["Contaminated with diethylstilbestrol, warfarin and alprazolam","Recalled in 2002 and no longer made","Blood clots and bleeding reported"]},"route":"/technologies/pc-spes/","neighbours":{"technology":[{"id":"alternative-medicine-instead-of-treatment","kind":"technology","name":"Alternative medicine used instead of standard treatment","route":"/technologies/alternative-medicine-instead-of-treatment/"},{"id":"androgen-deprivation","kind":"technology","name":"Androgen deprivation & AR pathway inhibitors","route":"/technologies/androgen-deprivation/"},{"id":"lycopene","kind":"technology","name":"Lycopene","route":"/technologies/lycopene/"},{"id":"selenium-supplements","kind":"technology","name":"Selenium supplements","route":"/technologies/selenium-supplements/"},{"id":"traditional-chinese-herbal-medicine","kind":"technology","name":"Traditional Chinese herbal medicine alongside treatment","route":"/technologies/traditional-chinese-herbal-medicine/"}],"cancer":[{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"section":[{"id":"hormonal","kind":"section","name":"Hormonal Therapy","route":"/fronts/hormonal/"},{"id":"supportive-care","kind":"section","name":"Supportive Care & Survivorship","route":"/fronts/supportive-care/"}],"drug":[{"id":"diethylstilbestrol","kind":"drug","name":"Diethylstilbestrol","route":"/drugs/diethylstilbestrol/"}],"bottleneck":[{"id":"b-misinformation","kind":"bottleneck","name":"Misinformation and unproven therapies","route":"/bottlenecks/b-misinformation/"}]}}