Magnesium helps to dissolve calcified fibroids, but not alone... a full protocol of Dr. Sircus' must be utilized, and this would include iodine (which is well known to reduce various types of hardened tumors as well as non-hardened), sodium bicarbonate, and various vitamins and minerals.
In addition, by drinking magnesium bicarbonate water daily you can eliminate calcifications in your body. See: http://magbicarb.com/ for Dr. Sircuses current recommendations for decalcification.
Please read this article on how magnesium assists in dissolving calcifications:
That explains it quite well though our recommendation for drinking magnesium bicarbonate water has taken priority over sodium thiosulfate.