What is the average satisfaction level with Botox?

I have persistent wrinkles between my eyebrows because of a habit of frowning when I concentrate or get angry. It stresses me out whenever people occasionally ask if I'm angry, and I feel like my expression is getting fiercer. I think I need to seek medical help before it's too late.

I looked it up and heard that Botox is the best treatment for frown lines, but I'm a bit worried because I've also heard that if administered incorrectly, it can make the eyelids feel heavy. Should I seek out a doctor who is skilled at administering Botox and has a lot of experience for this?

I am also curious if there is really a difference between domestic and imported Botox.

Please let me know if the pain is manageable without anesthetic cream, and how often I need to receive follow-up treatments to maintain satisfaction with the Botox.