There are many species of Aloe Vera, they are not all edible and they can be difficult to identify. To be on the safe side, it is suggested to buy an edible Aloe Vera plant from a reliable source. Aloe Vera has thick skin and spines. It can be eaten raw, with or without the skin. However, the spines must be removed. Aloe Vera skin contains a yellow sap called Aloin. Taking Aloin in excess amount can cause diarrhea.