They are made from the same type of material as our cell membranes, phospholipids. These phospholipids are derived from lecithin, which comes from oil extracted from non-GMO soy, not soy protein. Soy allergies typically come from the protein.
Their unique structure allows them to encapsulate biologically active ingredients. In this case they keep glutathione in its “reduced”, or biologically active state. They are very stable, which allows for use in an oral drink.