We’re very good at pushing through fatigue, stress, poor sleep and the feeling that something just isn’t right. But by the time the body starts yelling, it may have been whispering for quite a while. What if better health sometimes begins simply by paying attention?

Magnesium is everywhere right now — for sleep, stress, muscle cramps and more. But do you actually need a supplement? Here’s how to think about magnesium intake, testing, different forms, dosage and what you’re actually trying to accomplish.