Its for high blood pressure, they have also used it for insomnia, and adhd in children, dosing for wd's are usually .4mgs .. I have tried it.. It will help with the chills, watery eyes, and runny nose.. It wont help with the cramps!!! Nor the lower back pain!!! It also gives you dry mouth. I could fall asleep for a lil bit, but would wake back up very uncomfortable!! I don't know how it works for others though. Read up on it!! When they gave it to me, I googled it!!!