Natural Progesterone for the Treatment of Recurrent Glioblastoma

Inclusion Criteria: * Patients must have pathologic confirmation of a glioblastoma or gliosarcoma diagnosis at initial surgery or second or later surgery * Patients may have had up to two previous salvage agents administered for treatment of recurrent GBM (may be at 1st, 2nd or 3rd recurrence) * Patients must be \>= 18 years of age * Patients must be able to have magnetic resonance imaging (MRI) scans for disease follow up * Recurrent GBM must consist of a minimum of 1 cm\^3 of contrast enhancing disease on high resolution T1 post-contrast sequence as defined on pre-treatment MRI obtained within 14 days of initiating therapy * White blood cell (WBC) \>= 3,000/uL (=\< 14 days prior to registration) * Absolute neutrophil count (ANC) \>= 1,500/uL (=\< 14 days prior to registration) * Platelet count of \>= 75,000/uL (=\< 14 days prior to registration) * Hemoglobin \>= 9.0 gm/dl (=\< 14 days prior to registration) (transfusion is allowed to reach minimum level) * Aspartate aminotransferase (AST) /alanine aminotransferase (ALT) =\< 2.0 x upper limit of normal (UNL) (=\< 14 days prior to registration) * Bilirubin =\< 2 x UNL (=\< 14 days prior to registration) * Creatinine =\< 1.5 mg/dL (=\< 14 days prior to registration) * Patients must have a life expectancy of \>= 12 weeks * Patients must have a Karnofsky Performance Status (KPS) \>= 60 * Patients who are women of childbearing potential must have a negative pregnancy test documented =\< 14 days prior to registration and agree to…