Again, you won't get drunk more quickly on a plane. But lack of food and the aforementioned dehydration can make the effects of altitude stronger, thus making a single in-flight drink feel a lot boozier.

Scientifically speaking, the alcohol itself doesn't become "stronger," but your body’s reaction to it changes due to the cabin environment. Most airplane cabins are pressurized to an altitude of 6,000 to 8,000 feet, which leads to lower oxygen levels in your blood (mild hypoxia). This state can mimic and amplify the effects of intoxication, such as dizziness and impaired judgment, making you feel drunker faster than you would at sea level. Additionally, cabin air is incredibly dry—often with less than 20% humidity—which causes rapid dehydration. Since alcohol is a diuretic, it worsens this dehydration, leading to more intense headaches and fatigue. While your Blood Alcohol Content (BAC) remains mathematically the same regardless of altitude, the combination of lower oxygen, dry air, and often an empty stomach means that "one drink in the air feels like two on the ground." It is highly recommended to drink a glass of water for every alcoholic beverage consumed during a flight to mitigate these effects.