The phytochemicals in pumpkin seeds may reduce the effects of dihydrotestosterone on the prostate. They may also block the conversion of testosterone into dihydrotestosterone. Zinc is Effects of pumpkin seed in men with lower urinary tract symptoms due to benign prostatic hyperplasia in the one-year, randomized, placebo-controlled GRANU study 2015;94 (3):286-95. doi: 10.1159/000362903. Epub 2014 Sep 5. Winfried Vahlensieck Christoph Theurer 10.1159/000362903 Dosage and Preparation. Risk of Overdose. Pumpkin seed oil, also called pepita oil, is used in cooking and as a health supplement. It's thought to lower cholesterol, ease symptoms of an enlarged prostate, reduce hot flashes, and reverse hair loss. Research shows that Pumpkin Seed Extract can reduce prostate growth from non-cancerous tumors known as benign prostatic hyperplasia (BPH), which occurs in most men past 50. Research found that pumpkin seeds' polyphenols and other compounds may protect against prostate cancer. In one study, five different pumpkin seed extracts were evaluated for their effect on prostate cancer cells. All of the extracts inhibited the cancer cells from increasing in number. WLcni2o.