Royal jelly

Royal jelly is a secretion of honey bees, produced by glands in the heads of young nurse bees and fed to larvae and to adult queens. All larvae in a colony receive it for the first days, but only queen larvae continue to be fed it in large quantity, and that feeding helps push a female larva toward queen development with fully formed ovaries. By weight it is about two thirds water, with roughly one eighth protein, about eleven percent simple sugars and a few percent fatty acids including 10-hydroxy-2-decenoic acid. Beekeepers harvest it from queen cells when larvae are about four days old, and a well-managed hive yields around 500 grams in a season, so it must be kept cold. It is sold as a dietary supplement, although European regulators found no support for health claims, and it can cause allergic reactions.