Abstract: A method for enlarging a breast includes the step of administering to a subject in need thereof a composition that includes a fine particle of calcium phosphate. The fine particle of calcium phosphate may be a fine particle of hydroxyapatite. An average particle size of the fine particle of calcium phosphate is 10 to 1,000 nm. The fine particle of calcium phosphate may be a sintered body. The sintered body may be manufactured by a method including: a mixing step in which a primary particle containing calcium phosphate is mixed with a fusion inhibitor, and a sintering step in which the mixed particle obtained by the mixing step defined above is exposed to a sintering temperature.