NAC and Glycine
NAC and glycine seem to make me sleep well and feel refreshed. Together they continued healing a facial dimple where NAD stopped. 600 mg was good; more, up to 2400 mg, made my face puffy and caused pressure in my head. Large amounts seemed to stop the muscle-building effects of B12. The combination helped my body keep going after a hard day's work. When I used NAC without glycine, I became weak and had difficulty walking uphill.