We appreciate Dr. Gupta’s comment on our article.1 The study of the effects of alcohol is challenging. Ethical concerns would not allow a “randomized controlled hangover,” in which participants would consume a controlled amount of alcohol. The goal of gaining new knowledge should never surpass the need to protect the rights and health of our patients.2 Some of the mentioned confounders3 were controlled in our study.1 We excluded participants who did consume other drugs. In addition, no patients declared prior history of hepatic, endocrinologic, or renal disorders. However, we agree that the observational nature of the study implies that all the hypotheses are merely speculative. To properly associate the clinical presentation of alcohol-induced headache (AIH) with the effect and degree of dehydration, blood and urine osmolarity and sodium levels should be measured regularly during the study.4 Measurement of plasma arginine vasopressin (AVP) concentration is technically difficult.