When worker bees decide to make a new queen, either because the old one is weakening, or was killed, they choose several small larvae and feed them with copious amounts of royal jelly in specially constructed queen cells. This type of feeding triggers the development of queen morphology, including the fully developed ovaries needed to lay eggs.

oyal jelly has been reported as a possible immunomodulatory agent in Graves' disease.^[8] It has also been reported to stimulate the growth of glial cells^[9] and neural stem cells in the brain.^[10] To date, there is preliminary evidence that it may have some cholesterol-lowering, anti-inflammatory, wound-healing, and antibiotic effects, though the last three of these effects are unlikely to be realized if ingested (due to the destruction of the substances involved through digestion, or neutralization via changes in pH).^[11] Research also suggests that the 10-Hydroxy-2-decenoic acid (10-HDA) found in royal jelly may inhibit the vascularization of tumors.^[12] Royal jelly has also been hypothesized to correct cholesterol level imbalances due to nicotine consumption.^[13]

There are also some preliminary experiments (on cells and lab animals) in which royal jelly may have some benefit regarding certain other diseases, though there is no solid evidence for those claims, and further experimentation and validation would be needed to prove any useful benefit.

In holistic healing circles and popular alternative medicine folklore, royal jelly is believed to have anti aging properties stemming primarily from its amino acid content and broad spectrum of vitamins and minerals. Its reputation for providing fertility and libido assistance is also gaining traction within the holistic community, though little or no clinical research exists to support these assertions.^[14] Royal jelly is also widely used as a component in skin care and natural beauty products.

Royal jelly may cause allergic reactions in humans ranging from hives, asthma, to even fatal anaphylaxis.^{[15][16][17][18][19][20]} The incidence of allergic side effect in people who consume royal jelly is unknown. However, it has been suggested that the risk of having an allergy to royal jelly is higher in people who already have known allergies.^[15]