Your morning coffee might actually change the smell of your urine — and here’s why this surprising phenomenon has both doctors and coffee lovers curious.

Every morning, millions of people start their day with a steaming cup of coffee. For most, it’s a comforting ritual they can’t skip. But few realize that this beloved drink can have an unexpected effect on the body. According to doctors, coffee can actually alter the odor of your urine.

This phenomenon is real, and more and more people are noticing it. Some detect a strong or unusual smell after drinking coffee, while others never make the connection. Yet science has a simple explanation.

Why coffee changes the smell of urine

Coffee contains several volatile compounds. Once ingested, these compounds quickly enter the bloodstream, are filtered by the kidneys, and then eliminated through urine. The result? A stronger — and sometimes unpleasant — odor.

Caffeine also acts as a diuretic, meaning it makes you urinate more often. That increased frequency can make the scent more noticeable, as the concentration of odor-causing compounds in the urine rises. If coffee is consumed on an empty stomach, the smell can become even more intense.