No notable side effects have been reported in the GlyNAC literature, although there have been some documented instances of NAC causing nausea, vomiting, and diarrhea.[1][2]
When NAC or GlyNAC are taken intravenously, NAC overdose is possible, and can result in red blood cell breakdown (hemolysis), low blood platelet count (thrombocytopenia), kidney failure, and possibly death.[3]