GNC launches its solution for cheap, poorly absorbed Magnesium Glycinate

Magnesium Glycinate has surged in popularity for sleep. Social media users have questioned some brands claiming 22%+ elemental magnesium, above the ~14% theoretical max for pure, anhydrous bisglycinate. Higher yields may point to other salts. GNC's PureGlycinate has 12% elemental magnesium, in line with pure glycinate, giving shoppers a clear way to compare forms and claims.