Thanks for asking at healthcare magic I read your question and I understand your concern. Both norethindrone and lo Llstrin Fe donot not cause significant weight gain (norethindtone) progesterone doesn t cause much weight changes compared to lo Loestrin Fe (ethinyl estradiol, norethindrone, ferrous fumarate) although contains estrogen in very small amount but contains norethindrone as well... It affects mostly blood pressure level, aggravates heart disease, causes clotting disorder like deep vein thrombosis, cancer in long standing cases, triggers migraine.. But there are many causes of weight gain besides pills, Hypothyroidism, polycystic ovarian syndrome, Cushing syndrome, depression, behavioral problems... I would suggest you to have a thyroid function tests profile, ultrasonography of abdomen and if these were normal then wait for month as sometimes estrogen and progesterone imbalance the harmonal level transiently that settles down in a month or two.. Check your weight weekly, take modified Atkins diet that is low carbohydrate and high protein diet... continue your daily exercise Keep diary of what you eat... Hope it helps best Don t forget to rate this answer and to close the discussion at healthcare magic Take your best care Regards Dr Ejaz