Gamma cyclodextrin is a ring shaped carbohydrate that carries other nutrients. It does not do much on its own. Supplement makers use it to help deliver ingredients like CoQ10, resveratrol, or certain vitamins. You will typically find it inside a finished blend, not sold by itself.
The body digests very little of it. Most passes through your system intact. Take it according to the label on your specific product, with food or without.
Watch the active ingredient it carries rather than the cyclodextrin itself. People with rare starch or glucose absorption issues should take note.