Which drug is the most commonly used drug among teens?

Hey there,
The most common ones are Alcohol and Tobacco followed by marijuana.

Hope this helps :))

~Top♥

The most common drug would be marijuana 

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases.