It's not a matter of just taking something.
You have to know what you want, who you are.
Sounds like he wants a shortcut to something.
There aren't any.
Without specific goals in mind, there is nothing to take.
Never self medicate.
If it means a lot to him, he is going to need support before anything else.
Send him here. There is a ton of information, and many people who will help.
A therapist who understands or better yet specializes in Trans* people would be a start.
He needs to take that first step, that and support of friends and family if he can get it, is what he can take.
Anything else will put him at risk of being hurt.
Ativan