Carrageenan is a polysaccharide derived from seaweed (irish moss.) It is used as a thickening agent for the softgel capsules. It is used as an ingredient (food additive) all over the world for more than hundred years. It is a versatile fiber used in a variety of foods and dietary supplements.
We use a carrageenan extract for our plant based capsule (not for the oil). Currently this is the only ingredient that makes it possible to produce a vegan soft gel capsule. The shell of the capsule contains about 60 milligrammes of carrageenan. Without it the capsule would be too hard.
More (scientific) information about carrageenan can be found in the attachments.