Can turmeric and metformin delay prostate cancer relapse?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 18 years of age or older. * History of prior prostatectomy and/or radiation therapy to the prostate. * Currently have rising PSA levels ≥ 0.2 ng/ml if they have undergone radical prostatectomy, or a PSA ≥ nadir + 2 if they have received only radiotherapy. Patients who were not offered salvage radiotherapy as an alternative treatment will be considered ineligible (due to a high PSA, other medical concerns). * Currently have at least 2 consecutively rising serum PSA levels more than 1 week apart * Currently have a PSA doubling time \< 9 months obtained within 60 days of consent. * Eugonad with testosterone \> 150 ng/dl at time of consent. * Prior ADT (including iADT) for up to 24 months in association with definitive treatment is permitted if completed at least 12 months prior to consent. * Eastern Cooperative Oncology Group (ECOG) performance status 0 - 1. * Willing to take study agents at the dose specified with meals. * Willing to discontinue current vitamin/mineral supplements and use only those provided by study. Herbal supplements may still be used. Exclusion Criteria: * Current Chronic Lymphocytic Leukemia (CLL), Monoclonal Gammopathy of Unknown Significance (MGUS), Renal Cell Carcinoma (RCC) or another cancer requiring active treatment. Indolent or stable malignancies such as non-melanoma skin cancers are allowed. * Any active or deteriorating liver or renal disease, Human Immunodeficiency Virus (HIV), Hepatitis B, Hepatitis C or bone marrow deficiency. * Any history of allergic reactions attributed to turmeric, metformin, or other compounds of similar chemical or biologic compositions. * History of lactic acidosis or risk factors for lactic acidosis (e.g., renal impairment, concomitant use of carbonic anhydrase inhibitors such as topiramate, hypoxic states such as acute congestive heart failure, excessive alcohol intake, and hepatic impairment). * Any other condition that, in the opinion of the investigator, might interfere with the safe conduct of the study.