There are only a few sex references throughout the entire series.

There is a clip of full rear nudity in season 2 and 3.

There's blood and gore.

In one episode, a man had his finger penetrated violently. His nail somewhat became separated from his finger. This can be hard to watch.

Mild to moderate swearing. You can hear the word fuck once or twice in season 1.

The older woman in the future, Dr. Jones, smokes and drinks.

Several people are seen drinking.

Jennifer's craziness might scare young children.

Cassie had a illusion about a red forest. This can be creepy and frightening.