Chemotherapy-induced alopecia is a distressing problem to the cancer patient for which currently there is no effective preventive measure. Recently ImuVert, a biologic response modifier, has been shown to protect from cytarabine-induced alopecia in the young rat model, but not from alopecia induced by cyclophosphamide. In the present study, the rat model was used to examine the effect of N-acetylcysteine on the course of alopecia from cyclophosphamide and of ImuVert plus N-acetylcysteine on alopecia induced by cytarabine-cyclophosphamide combination. The following observations were made: (1) Cyclophosphamide-induced alopecia could be effectively prevented by N-acetylcysteine, administered parenterally or applied topically in liposomes. (2) Alopecia caused by the combination of cyclophosphamide and cytarabine could be prevented by the parenteral or topical administration of ImuVert plus N-acetylcysteine. The potential applicability of these observations to the clinical settings remains to be determined.