Magnesium glycinate is the easiest form of magnesium to absorb for most people.
"I love a magnesium glycinate. There's lots of different kinds, but glycinate's just the easiest to absorb for most people." (said at 0:49:40)
While organic forms of magnesium (including magnesium glycinate/diglycinate, citrate, and lactate) generally exhibit higher bioavailability and better gastrointestinal tolerance than poorly soluble inorganic salts such as magnesium oxide, clinical trials and systematic reviews do not show that magnesium glycinate is uniquely superior or the 'easiest to absorb' among all forms for most people. Systematic reviews indicate that multiple organic formulations show high and comparable bioavailability, and factors such as baseline magnesium status and single-dose size influence absorption more heavily than differences between organic chelates.
- contradicts: Intestinal Absorption and Factors Influencing Bioavailability of Magnesium-An Update. (Current nutrition and food science 2017)
"Due to the lack of standardized tests to assess Mg2+ status and intestinal absorption, it remains unclear which Mg2+ binding form produces the highest bioavailability." (abstract, conclusions, passage verified)
pubmedfull study (doi) - context: Bioavailability of magnesium food supplements: A systematic review. (Nutrition (Burbank, Los Angeles County, Calif.) 2021)
"Inorganic formulations appear to be less bioavailable than organic ones, and the percentage of absorption is dose dependent." (abstract, results, passage verified)
pubmedfull study (doi)