When best to take Lexapro?

Hi, Step67!
It all depends on how you respond to the medication. Lexapro can make some people sleepy but it can also cause insomnia in others:
"Very common (10% or more of users): Insomnia (up to 14%)"
"Very common (10% or more): Somnolence (up to 13%)
There's a good chance you won't have either of these side effects but if it does make you tired take it at night. If you can't sleep take it in the morning.