2 forms studied
Does magnesium help with irregular digestion?
Yes — but only in one form. Magnesium Citrate is the one that was tested, and the others sold for this do not carry the same evidence.
Form by form
Strongest first. Evidence for one salt or ester is not evidence for another, so each is rated on its own trials.
Magnesium CitrateSolid
Trials used 500–2000 mg · 4 studies · tested as magnesium oxide
Magnesium GlycinateNot verified
Trials used 200–400 mg · 2 studies · tested as Magnesium oxide (the only form with RCT evidence for constipation/irregular digestion)
Worth knowing before you buy. Magnesium Glycinate is widely sold for irregular digestion, but the trials behind that use tested magnesium citrate instead.