干根茎含总皂甙元3.86%,从中得薯蓣皂甙元2.12%。尚有替告皂甙元、多种皂甙和β-谷甾醇葡萄糖甙。
根茎和根含3-(4-羟基苯基)-(E)-2-丙烯酸甲酯[methyl-3-(4-hydroxyphenyl)-2(E)-propenoate],姜黄素(curcumin),邻苯二甲酸双(2-乙基已醇)酯[bis(2-ethylhexylphthalate],5α-9(11)-豆甾烯-3β-醇[5α-stigmast-9(11)-en-3β-ol],13-甲基-十五(烷)酸十四醇酯(tetradecyl-13-methylpentadecanoate),11-甲基十三(烷)酸十四醇酯(tetradecyl-11-methyltridecanoate),14-氧代二十七(烷)酸(14-oxoheptacosanoic acid),14-氧代二十三(烷)酸(14-oxotricosanoic acid),15-氧代二十八(烷)酸(15-oxooctacosanoic acid),三十(烷)酸(triacontanoic acid),三十(烷)醇(triacontanol),31-去甲环木菠萝烷酮(31-norcycloartanone),环木菠 萝灶醇(cycloartanol),环木菠萝醇(cycloartenol),环鸦片甾烯醇(cyclolaudenol),三十三(烷)酸甲酯(methyltritriacontanate),8-羟基古二烷-25-酮(8-hydroxytriacontan-25-one)三十(烷)酸甲酯(methyl triacontanoate),24-羟基三十一烷-27-酮(24-hydroxyhentriacontan-27-one),24-羟基三十烷-26-酮(24-hydroxytriacontan-26-one),谷甾醇(sitosterol),β-谷甾醇(β-sitosterol),胆甾醇(cholesterol),菜油甾醇(campesterol),豆甾醇(stigmasterol),羊毛甾醇(lanosterol),薯蓣皂甙元(diosgenin),替告皂甙元(tigogenin),甲基原薯蓣皂甙(methylprotodioscin),薯蓣皂甙的前皂甙元A(prosapogenin A of dioscin),薯蓣皂甙的前皂甙元B(prosapogenin B of dioscin),薯蓣皂甙(dioscin),纤细薯蓣皂甙(gracillin),葡萄糖(glucose),鼠李糖(rhamnose)及多种生物碱。