Mefenamic acid
"I've took this for the first time today. I was prescribed it after very painful periods and advised to take when I have pain for as many days as I need (the first day being so bad I am crying in pain and having time off work) I started to get period cramps today took 1 dose and within an hour had no pain at all. I usually have vomiting and diarrhea with the first day but this has disappeared as well. It has also made my period so much lighter. Best medication I have had for period pain."