Diosgenin (DI) and trigonelline (TRG) are the main bioactive compounds of fenugreek seed. A micro-extraction method using magnetic nanocomposites coupled with ion-pairing reversed phase HPLC (RP-HPLC) method was used to determine the analytes in rabbit plasma. The main PK parameters after oral administration of pure DI and the extract were: C max : 0.48, 0.057 µg/ml; t max : 1, 2 h; and t 1/2 β: 6.23, 15.04 h, respectively. Pure TRG and the extract PK parameters were: C max : 0.121, 0.081 µg/ml; t max : 1.30, 1.30 h; and t 1/2 β: 20.06, 24.70 h, respectively. Generally, the PK profile of the two compounds was best fitted on the two-compartment model.[Formula: see text].