Two couples swim naked in a pool. No nudity is shown, they are under the water.

It is minorly implied that a man between two gravestones is receiving oral sex, yet two other characters block the view below his waist. His facial expression is what implies it.

Full frontal nudity is shown for a little less than a minute during an LSD scene.

A couple of sexual references

One of the first songs in the film uses the word goddamn multiple times.

3 uses of "d*mn", 1 use of "*sshole", 1 use of "h*ll", 4 uses of milder name-calling (hick, weirdo). Someone flips off another person.

We watch a drug deal happen. Some characters sample the cocaine on the spot.

Marijuana is smoked throughout the entire movie.

Cocaine is used in mostly the beginning scenes.

Alcohol is consumed in a few scenes.

The characters take LSD and the following sequence is a cinematic representation of an acid trip.

A good deal of the substance abuse is reported to have been unsimulated.

The scene where the characters get beaten by people, may upset some viewers

The verbal harassment against Billy and long-haired men in general may upset some viewers.

The acid freakout scene is probably disturbing. The ending scene could upset and shock some viewers

The LSD acid trip scene lasts around 5 to 7 mins of total randomness but hallucinations are shown.