On a 1-10 scale I'd have rated it at least a 6, usually 7 or 8, and sometimes pushing a 9. (This is from someone who has a history of kidney stones
with complications that once required a 17 day hospitalization.) Now I still have it nearly every day, but for less than an hour almost every day that it occurs, and at a level of 2 to 4 for severity.
I started with 300 mg 1x/day, and was to do three days, then 2x/day for 3 more, then 3x/day. Well, to make a long story short (HA! Me?!