My boyfriend was allergic to honeybees and got the desensitizing shots when he was a kid (dad kept bees). He doesn't know the eficacy of the shots at this point, twenty five years later, but he carries the pink benadryl with him. He caught a wasp in the mouth last month and the benadryls made him a little goofy but he was able to get home okay and zonked out on the couch afterward.