Glycerin (glycerol) is NOT a sugar alcohol. Sugar alcohols are derived from sugar. Glycerol is derived from fat and part of the fat called triglyceride which is your stored body fat.

Sugar alcohols should be eaten in moderation and do turn into glucose, but do so very slowly since they bypass the small intestine where fat and carbohydrate are metabolized. In other words, a large quantity of sugar alcohols will take you out of ketosis. The sugar alcohols (polyols) are sorbitol, maltitol, zylitol, lactitol and mannitol.

Glycerin is not a sugar alcohol.