Will 'norethisterone' Be Helpful In Treating Amenorrhea?

hi doctor.im 28 yeras old, 5.4 feet and 80 kg, i had never problem of irregular menstural cycle...i took a diet plan for weight loss which included protein diet and few medicines which were told they had no side effects i used them for 1 and half month but have problem of ammonorhea. i have left them and not having my cycle for three months nw i have been prescribed norethisterone for starting regular periods for 5 days,will it be effective?