Home Diabetes Glossary insulin antagonist insulin antagonist Saturday,January 4, 2023 ByDiabetesCare.net by DiabetesCare.net | Jan 4, 2023 | 0 comments something that opposes or fights the action of insulin. Insulin lowers the level of glucose (sugar) in the blood, whereas glucagon raises it; therefore, glucagon is an antagonist of insulin. Submit a Comment Cancel replyYou must be logged in to post a comment.