The present invention addresses the problem of providing a novel therapeutic agent for alopecia which: is safe and effective against alopecia, particularly alopecia areata, male pattern baldness in men, male pattern baldness in women, female pattern baldness, postpartum alopecia, seborrheic alopecia, alopecia pityrodes, alopecia senilis, alopecia due to chemotherapeutic agents, and alopecia due to radiation exposure； is also effective for subjects who are resistant to minoxidil and finasteride treatments； and is free of side effects such as itching, irritation and feminization, has no contraindications, reduces dandruff, has a therapeutic effect on grey hair, and has no long-term loss in therapeutic effect on alopecia even when stopped. The means for solving this problem is a therapeutic agent for alopecia that uses a C-type natriuretic peptide (CNP) or a B-type natriuretic peptide (BNP), derivatives of these natriuretic peptides (NPs), chimeric peptides of these NPs or derivatives of these NPs as active ingredients.
