Most commercially available marshmallows contain gelatin, which is a jelly-like substance derived from the collagen of the bones of many animals including fish, cattle and pigs. While much gelatin is derived from the bones of pigs, no meat is present in the sweet marshmallow product.
Commercially made marshmallows are an evolution of the original pink-flowered Althaea officinalis mallow plant, an edible plant popular among the ancient Egyptians and often used as a remedy for a number of maladies. Modern marshmallows are made primarily from sugar, egg whites and gelatin derived from the collagen of a number of animals, the latter of which acts as a binding agent. Marshmallows are popular and are eaten on their own as well as serving as the base for a number of treats including s'mores and Marshmallow Peeps.