hello, as you are saying menorrhagia & thyroid issue, you may be suffering from hypothyroidism, hypothyroidism slows down metabolic processes of the entire body including pituitary and gonadal hormones causing sharp drop of estrogen and progesterone levels. Endometrium becomes dysfunctional, resulting in increased expulsion of it .Coupled wth this anemia and limited intake of calcium and fat soluble vitamins increases bleeding time and uterine flow. The net result is shortened menstrual cycle and increased flow. femilon which is prescribed to you is to regularise your menstural cycles. you consult your physician & get treated for your thyroid problem. Hope it helps, Take care & plz do keep me posted on how you doing or if you have any additional doubts Kind regards