How much blood does a woman lose during her menstrual cycle?

2-3 ounces. Sometimes a little more, if you are worried it is too heavy your gyn can do a work up and there are many options ranging from bc pills, lysteda, endometrial ablation which I do on many of my patients , wear a balloon is palced in teh uterus for 8 minutes and it gets rid of the lining so no more periods if you are done with fertlity.