Magnesium citrate is sometimes sold under the brand "Natural Calm" and while I'm not sure if it actually does calm me down, I think the nighttime "potion" process is good for me.
I used to just mix it with water, but since the pandemic, I've wanted to boost my vitamin C intake and so I add a powdered version (as Calcium Ascorbate) which is easier to digest and naturally has C and calcium and as a bonus, makes for a pretty compelling fizzy drink.