Magnesium Oil Ultra Spray with MSM by Ancient Minerals$15 for 4oz Why You Need It: Magnesium is responsible for over 300 enzymatic systems in the body; it has been used to treat restless leg, stress, sleep, muscle pain, and cramps. Why We Love It: I love a multi use product. I get terrible period cramps, and this product has helped me. I have sprayed it right on my stomach, and it's fast acting. I also use this before bed to help with sleep. This particular brand and type is very easily absorbed.