A 21-year-old Japanese woman developed life-threatening starvation ketoacidosis after five weekly injections of tirzepatide (2.5 mg), losing 21 kg in one month while combining the medication with carbohydrate restriction. She presented with severe metabolic acidosis (pH 7.22), hypoglycemia, and markedly elevated ketones, requiring emergency glucose infusion for rapid recovery within 12 hours. This represents the first documented case of tirzepatide-induced starvation ketoacidosis in an East Asian population and highlights a concerning blind spot in the widespread adoption of GLP-1 receptor agonists for weight management. The case underscores how tirzepatide's powerful appetite-suppressing effects can create a perfect storm when combined with dietary restriction, leading to dangerous caloric deprivation that triggers ketogenesis. For the millions now using tirzepatide and similar medications like semaglutide for weight loss, this case serves as a critical warning about monitoring for excessive weight loss velocity and gastrointestinal side effects. Emergency physicians must now consider starvation ketoacidosis in their differential diagnosis for patients presenting with vomiting and metabolic acidosis while using these increasingly popular medications, particularly in non-diabetic individuals who lack the protective glucose monitoring typically associated with diabetes care.