The invention provides a method for preventing or treating male erectile dysfunction or female sexual arousal disorder by administering an effective amount of one or more factors from a group of factors including vascular endothelial growth factor, brain-derived neurotrophic factor, basic fibroblast growth factor, neurotrophin-3, neurotrophin-4, or angiopoietin-1, wherein the factor is a full length protein or a nucleic acid encoding the factor, or a functional derivative or fragment thereof, or an agent that enhances production and/or male erection or female sexual arousal stimulating function of the factor(s). Combinations, kits, and combinatorial methods are also provided.