The present invention provides a novel therapeutic agent for alopecia. The therapeutic agent of the present invention is effective and safe for treating alopecia, especially alopecia areata, androgenetic alopecia of male, androgenetic alopecia of female, female pattern alopecia, postpartum alopecia, seborrheic alopecia, alopecia pityroides, senile alopecia, alopecia caused by chemotherapy drugs or radiation exposure, and is effective for treating patients showing therapy resistance to minoxidil or finasteride. The therapeutic agent of the present invention has no side effect, such as etching, stimulating or feminizing, or contraindication. The therapeutic agent is also useful for the treatment of dandruff and white hair. Additionally, the therapeutic agent of the present invention can retain effectiveness for a long time even if the patient discontinues using it. The therapeutic agent for alopecia of the present invention comprises C-type natriuretic peptide or B-type natriuretic peptide, derivatives of said NPs, chimeric peptides of said NPs, or derivatives of the chimeric peptides of said NPs as an active ingredient.
