I have been using natural remedies to help with my menstrual cramps since I was required to go off of Advil last year due to stomach bleeding. (I used to take 4 at a time, several times to manage pain). This is what my doctor prescribed:
Vitamin B1 (100 mg), daily
Magnesium Oxide (400 mg, 2x day, for one week before your period and then during your period only).
Pycnogenol (don’t remember the dosage, but take it daily)–this is made from tree bark I think; very effective especially if endometriosis may be involved.
Also fish oil or flax seed oil for Omega 3 (don’t recall dosage)
Just before my period I also stop eating meat–the prostoglandins in meat make cramps worse I think. At any rate, if I have not eaten meat the day before I find the cramps a lot less.
During my period I also apply a heating pad directly to my stomach or back depending on where the pain is.
Lastly, I am told that ginger also helps cramps. Use real ginger and boil some in hot water to make like a tea. Or if you can eat it, cut it into pieces like a pill or grate it into food or add it into vegetable juice. My physical therapist friends also recommend this for general muscle cramps.