At the end of the fourth week , patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI ( p < 0.001 ) , desire ( p < 0.001 ) , arousal ( p = 0.037 ) , lubrication ( p < 0.001 ) , satisfaction ( p < 0.001 ) and pain ( p = 0.041 ) domains of FSFI .