is it safe to expand my anus to accept a toy?

I personally would not try and go for much bigger than a large penis because I feel like any bigger and damage is much more likely (or long term issues). Other people seem to get along just fine, but I'm too risk adverse. How thick are we talking? Just take it slow and don't jump from small to very large sizes. Being gradual is key. I'm actually in the process of trying to expand as well haha. Good luck to you :)