although the studys arent conclusive i think i would stay away from sarcosine until more is known -from wilkipedia
Prostate cancer marker
In a paper published in the journal Nature in 2009, sarcosine was reported to activate prostate cancer cells and to indicate the malignancy of prostate cancer cells when measured in urine.[5] Sarcosine was identified as a differential metabolite that was greatly increased during prostate cancer progression to metastasis and could be detected in urine. Sarcosine levels were also increased in invasive prostate cancer cell lines relative to benign prostate epithelial cells.[6] Sarcosine levels seemed to control the invasiveness of the cancer.[5]
However, this conclusion has been disputed. A German research team reported a different result in 2010.[7] After measuring sarcosine levels in urine samples from prostate cancer patients, they concluded that measuring sarcosine in urine fails as a marker in prostate cancer detection and identification of aggressive tumors. In addition, another report concluded that serum sarcosine is not a marker for prostate cancer.[8] A review of the literature reached a similar conclusion.[