A method for treating alopecia and/or hair depigmentation includes administering to a subject in need of such treatments a synthetic peptide, which has an amino acid sequence that has 20-44 amino acid residues and includes at least 20 consecutive residues that has at least 90% amino acid sequence identity to residues 16-35 of SEQ ID NO: 10. Also disclosed herein are pharmaceutical compositions containing the synthetic peptide; and uses thereof. According to various embodiments of the present disclosure, the synthetic peptide is useful in treating alopecia and/or hair depigmentation in a subject.