Napiers Marshmallow SyrupA Soothing Syrup for Throat and Chest, made from Marshmallow Root. Our marshmallow syrup is a pleasant tasting extract made from marshmallow roots in a sugar base that can be used to mix into drinks, for baking or just sucked off the spoon! Marshmallow (Althaea officinalis) has been used for centuries as an ingredient in cough syrups and cough sweets as it is reputed to soothe the throat. It was also used in drink mixes to soothe an irritable stomach.