Royal jelly is the equivalent of breast milk for bees. It is produced by the hypopharyngeal glands located in the heads of worker bees and is the sole food for all bees during the first three days of their life in the egg stage. Workers are fed a mixture of royal jelly, pollen, and honey, while the queen will continue to be fed only royal jelly throughout her life.

Royal jelly is what determines, at a very early stage of development, whether the tiny larva will become a queen capable of laying eggs or a sterile worker. It is a source of proteins, amino acids, lipids, vitamins, and minerals. It is widely believed to have a beneficial effect on humans.