I only take 200-400mg per day, but then I get quite a bit of Mg in water (Apollinaris) and in food as I eat brown rice, nuts and legumes.

It really depends how much you are getting in total from all sources. If you are not getting much from other sources, you could try a bit more. The laxative effect of magnesium is usually a simple way to work out when it's too much - if you start to have sloppy BMs, you took too much - probably, unless you ate something funny as well, in case you wouldn't be sure!!!

You just gotta try it for a few days - but gradually increase - and then monitor how you feel.

amanda