A bee secretion marketed for hair growth and nourishment. There is no human evidence, and the one direct mouse study found it made hair thinner.
Royal jelly is the protein-rich secretion worker bees feed to queen larvae. Its 'queen bee' image drives claims that it nourishes hair and skin. In a 2025 study that tested it directly on hair growth, royal jelly applied to mouse skin produced thinner hair shafts and slowed hair follicle stem cells.
No human trials support hair or skin benefits of topical royal jelly. The direct animal evidence (mice, 2025) points toward thinner hair, the opposite of the claim.
Royal jelly applied to mouse skin produced thinner hair shafts and smaller hair bulbs, and suppressed hair follicle stem cell growth in mice and in culture: the opposite of the hair-growth claim.