A problem that the present invention is to solve is to provide: a main body of a peptide molecule which is effective for inhibition of various maladies such as osteoporosis, osteoarthritis and pressure ulcer, particularly, a dipeptide which is easy to absorb into a body in an intestine; a collagen peptide which comprises the dipeptide as an essential dipeptide; and a malady inhibitor which comprises the dipeptide as an essential effective component. As a means of solving such a problem, a collagen peptide according to the present invention is characterized by comprising a dipeptide having a structure of Hyp-Gly as an essential dipeptide. A dipeptide according to the present invention is characterized by having a structure of Hyp-Gly. A malady inhibitor according to the present invention is characterized by comprising a dipeptide having a structure of Hyp-Gly as an essential effective component.