The present invention describes a synergistic composition comprising of NK3 receptor antagonist or a pharmaceutically effective salts thereof and biguanides or a pharmaceutically effective salts thereof for the treatment of PCOS and related diseases. The present invention is directed to a synergistic combination comprising combinations of a NK3 receptor antagonist or pharmaceutically effective salts thereof and biguanides or pharmaceutically effective salts thereof in a single unit pharmaceutical composition. The invention is further related to methods of preparing such pharmaceutical composition in separate in either a kit form containing both the active agents and methods of treating a subject with the same.本發明係說明一種包含NK3受體拮抗劑或其醫藥上有效鹽類與雙胍類或其醫藥上有效鹽類用在治療PCOS(多囊性卵巢症候群)和相關疾病的增效組成物。本發明係關一種增效組合物,其包含呈單一單位醫藥組成物之NK3受體拮抗劑或其醫藥上有效鹽和雙胍類或其醫藥上有效鹽之組合。本發明尚關於分開製備此種醫藥組成物使其每一者為含有兩種活性劑之套組形式的方法,以及用該組成物治療受治對象的方法。