Let's clear something up about MTHFR. You've probably heard it talked about online. Sometimes it's overhyped. Sometimes it's ignored. The truth is somewhere in the middle. MTHFR is a gene that affects Glutathione supplementation (life altering reaction to SSRI) : r MTHFR MTHFR. And no I'm not cussing It's a gene involved in methylation basically how the body processes folate, regulates homocysteine, and handles detox pathways. About 3040% of people carry a mutation Methylation & MTHFR Gene Mutations Explained Converging Evolutionary, Environmental and Clinical Ideas on Folate Metabolism