Allergic reactions are the most common side effect. Allergic reactions from oral intake of royal jelly can range from very mild (e.g., mild gastrointestinal upset) to more severe reactions, including asthma, anaphylaxis (shock), intestinal bleeding, and even death in people who are extremely allergic to bee products.^6,7,8 People who are allergic to bee pollen, honey, or conifer and poplar trees should not use royal jelly orally. Topical use of royal jelly has been reported to cause skin irritations in some people.⁹