It is an object of the present invention to provide a new agent for the treatment of alopecia, the agent being not only effective and safe for, in particular, alopecia areata, androgenetic alopecia in a male, androgenetic alopecia in a female, female pattern alopecia, postpartum alopecia, seborrheic alopecia, alopecia pityroides, senile alopecia, cancer chemotherapy drug-induced alopecia, and alopecia due to radiation exposure, but also effective for a target having resistance to treatment with minoxidil or finasteride, there being no side effects such as an itching sensation, irritation, or feminization, and no contraindications, the agent suppressing dandruff or having a therapeutic effect for white hair, and the therapeutic effect for alopecia being maintained for a long period even when use of the agent is stopped.The solution means of the present invention is an agent for the treatment of alopecia containing as an active ingredient a C-type natriuretic peptide (CNP), a B-type natriuretic peptide (BNP), a derivative of these NPs, a chimeric peptide of these NPs, or a derivative of a chimeric peptide of these NPs.
