I’ve recently seen an increase in clients reporting headaches within 24 to 48 hours after injecting tirzepatide, whether they use Mounjaro for type 2 diabetes or Zepbound for obesity and weight management. Because headaches are not among the gastrointestinal side effects most commonly associated with tirzepatide, they can catch people off guard. You may wonder whether the medication is responsible or something else is going on. Emerging research suggests that headaches can occur in the days following an injection. Let’s explore what the evidence shows, why these headaches may happen, and what you can do to find relief.