I was using another brand for a long time but recently did some more reading online about muscle cramps. I have been exercising a lot lately and was experiencing cramping, especially at night. I learned that the type of magnesium you take is very important. Magnesium Glycinate is the best, according to what I found in my online search.
The brand I was using was good (Cramp Defense), but it is more expensive for less product and does not have Magnesium Glycinate as its main ingredient. So, I decided to give the Natural Foundation brand a try. I think it works better than my previous brand, and I am happy with the lower cost and greater quantity.
I would definitely recommend this product. Just don't skimp on how much you take—sometimes 4-5 for me if I am exercising hard, with a little food, milk, etc.