MTHFR trumps the biofilm building of magnesium, which really isn’t that big of a deal. The benefits of magnesium far outweigh the small biofilm component, because we want to keep you on your methyls and keep the detox pathways moving forward. Continue on magnesium glycerinate 400mg/day and the methyls. Magnesium glycerinate is the only form of magnesium I suggest ingesting when on a pathogen purge (others are doing magnesium oil externally).