Black Cohosh for Host Flashes Due to Androgen Deprivation Therapy

Inclusion Criteria: * Able to understand English or be wiling to use a trained interpreter * Diagnosis of prostate cancer * Receiving either Leuprolide or Degarelix,for prostate cancer treatment * Currently experiencing a minimum of 3 self-reported hot flashes within a 24 hour period * Eastern Cooperative Oncology Group (ECOG) performance status score \< 2 * Life expectancy \>3 months. * No grade 3 or higher toxicity from prior cancer therapies unless judged by the principal investigator to be clinically irrelevant to study procedures * At least four (4) weeks following prior major surgery * Serum testosterone concentration below castrate level (\< 30 ng/dL) at time of recruitment * Willing to provide written informed consent for participation in the study Exclusion Criteria: * Concurrent severe illness effecting ECOG performance status or life expectancy as determined by the principal investigator * Hormone refractory patients. Patients taking Enzalutamide or Abiraterone. * Active infection * Psychiatric illness or social situation that would limit safety and compliance with study requirements * Currently taking any pharmaceutical medications that have potential interactions with black cohosh as determined by the principal investigator * Currently taking any supplements that have potential interactions with black cohosh as determined by the principal investigator * Currently receiving any treatment for hot flashes or planning to initiate any treatment for hot flashes other than with study supplementation * ALT, AST, or Bilirubin \> 2 times their normal laboratory values in the past 3 months * Inability to complete the informed consent process or adhere to the protocol treatment plan.