The main difference between citrate and glycinate is tolerance and intended use. Magnesium citrate can have a more noticeable osmotic effect in the gut, which may increase bowel movements and can be useful for constipation-prone individuals. Magnesium glycinate is generally considered gentler and is often chosen for sleep or stress support and for people with sensitive digestion. That said, there is no universal rule—responses vary by person. A practical decision process is: (1) define your goal (sleep, cramps, constipation, general support), (2) plan the dose based on elemental magnesium, and (3) track tolerance and results over one to two weeks of consistent use. Very high doses can cause diarrhea with any form, so gradual titration is usually the safest approach.