AS101 is a tellurium based immunomodulator that inhibits the P13K/PTEN/Akt pathway and has anti-apoptotic and anti-inflammatory properties [37, 38]. AS101 has been shown to be protective against hematopoietic damage in mice treated with cyclophosphamide without adversely affecting treatment outcome [39-42]. It has also been shown to have anti-tumor effects in mice and human studies and synergistic effects with cyclophosphamide [39, 42-44]. Studies of gonadal protection in mice have similarly shown AS101 to protect against chemotherapy-induced follicular damage and reduce sperm DNA damage without interfering with cancer treatments [45, 46]. The proposed mechanism of action is inhibition of activation and loss of dormant primoridal follicles during chemotherapy as well as reduced apoptosis in the granulosa cells of growing follicles. AS101 can be administered systemically. Human studies further evaluating the effect on gonadal protection are warranted.