Here are some other options, depending on the context:
* юноша (yunosha) - young man (more formal)
* девушка (devushka) - young woman (more formal)
* подростки (podrostki) - teenagers (plural)
It's important to note that "teenager" in Russian can also be used to describe someone who is in their early 20s, especially if they are still considered to be young and immature.