- Mild
- In one episode Ross and Rachel drink lots of whiskey, tequila, beer and wine and get very drunk
- The boys drink beer often
- One episode is about Rachel smoking
- There are infrequent references to crack and weed
- A couple of episodes show people too drunk to think straight and do something stupid.
- There is a running gag about a main character being an ex-smoker and another about one of the character's parents being a secret smoker.
- Joke about planting PCP to attract police attention. It never happens and is just a comedic line.
- Alcohol consumption and characters get drunk sometimes.
- Some references in dialogue to marijuana, but no use is shown.
- Characters smoke cigarettes in several episodes; there is a recurring story arc that Chandler is an ex-smoker who frequently lapses under stress.
- One subplot of one episode is that Ross once lied to his parents about taking drugs and blamed it on Chandler
- In Season 6 Episode 19 We're told that That Ross smoked pot in college and his parents in walked and smelled Marjuina and Ross says Chandler smoked pot and got stoned and jumped out the window
- In season 5, Ross and Rachel become drunk and get married in Vegas