Inclusion Criteria:

          -  Men age ≥18 years who are fluent in English.

          -  Histologically confirmed prostate adenocarcinoma.

          -  Prior surgical castration or active ongoing use of androgen deprivation therapy (ADT)
             with expectation by the treating physician that patient would remain on ADT for the
             upcoming 12 months. ADT in the setting of definitive radiation therapy permitted.
             Concurrent treatment with androgen pathway inhibitors (examples include enzalutamide,
             abiraterone, darolutamide, apalutamide) permitted..

          -  Normal organ and marrow function function (labs within 30 days prior to study entry)
             as defined below:

        White blood cell count greater than or equal to 3,500/mcL (or 3.5 (x103)) Platelet count
        greater than or equal to 75,000/mcL (or 75 (x103)) Hemoglobin greater than or equal to >9
        g/dL Total bilirubin less than or equal to 2.5 X institutional upper limit of normal
        AST(SGOT)/ALT(SGPT) less than or equal to 2.5 X institutional upper limit of normal
        Creatinine less than or equal to 2.5 X institutional upper limit of normal

          -  Able to ambulate (use of assist device is acceptable).

          -  Able to cooperate with study-related activities.

          -  The effects of MGE on the developing human fetus are unknown. Men must agree to use
             adequate contraception (barrier method of birth control; abstinence) prior to study
             entry and for the duration of study participation.

          -  Ability to understand and the willingness to sign an IRB-approved informed consent
             document (either directly or via a legally authorized representative).

        Exclusion Criteria:

          -  Symptomatic metastatic disease requiring medical treatment (i.e., painful metastases
             to bone).

          -  Prostate cancer related surgery or radiation within 60 days prior to study entry.

          -  Documented rise in PSA (defined as rise of > 0.5 ng/mL) while on current prostate
             cancer therapy, determined by PSA values, at least one of which must be during the 6
             months prior to study entry PSA values must be at least 7 days apart.

          -  Planned cessation of ADT or planned use of cytotoxic chemotherapy (i.e., docetaxel)
             within 12 months after study entry.

          -  Ongoing use of any other investigational cancer-directed agents.

          -  History of allergic reactions attributed to compounds of similar chemical or biologic
             composition to MGE.

          -  Inability to swallow oral medications.

          -  Malabsorption due to bowel resection or gastrointestinal disease leading to
             uncontrolled diarrhea, or persistent nausea or vomiting requiring daily antiemetic
             therapy for symptom management within the past week.

          -  Uncontrolled intercurrent illness, including but not limited to: ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations that would limit compliance with
             study requirements.