Epidiolex (CBD) in Patients With Biochemically Recurrent Prostate Cancer

Inclusion Criteria: * Completion of localized therapy (prostatectomy or radiotherapy) for prostate adenocarcinoma (either histologically or cytologically confirmed) * Biochemical (PSA) recurrence, defined as: \* PSA of \>= 0.2 ng/ml that has increased above nadir following radical prostatectomy OR \* PSA increase of 2.0 ng/ml above post-therapy nadir after radiotherapy NOTE: PSA measured at two consecutive time points (separated by 4 or more weeks) is required in order to demonstrate the requisite increase in PSA * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Absolute neutrophil count \>= 1,500/microliters (at baseline \[pre-study\]) * Platelets \>= 80,000/microliters (at baseline \[pre-study\]) * Total bilirubin =\< institutional upper limit of normal (at baseline \[pre-study\]) * Aspartate aminotransferase (AST)(serum glutamic-oxaloacetic transaminase/alanine aminotransferase (ALT)(serum glutamate pyruvate transaminase) =\< institutional upper limit of normal (at baseline \[pre-study\]) * Glomerular filtration rate (GFR) \>= 30 mL/min/1.73 m\^2 using the Cockcroft-Gault formula (at baseline \[pre-study\]) * Patients with a prior or concurrent malignancy (non-prostate) whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen as determined by the treating physician are eligible * Given that worsening of an underlying state of mental depression or suicidal ideation…