Does Botox really work?

Lately, I've been hearing a lot of talk about Botox from people around me. Friends who have had it often say that their faces look much more refined or that their jawlines have become slimmer. So, I became interested in Botox myself, but now that I'm actually trying to look into it, there are many things that are confusing about just how effective it really is.

I have heard that getting Botox makes the face look smaller because it reduces muscle mass, but I am curious whether this is temporary or if the effect is maintained with consistent injections. Some people say the effects are natural and they are highly satisfied, while others say there wasn't as significant a change as they expected, which makes me even more conflicted.

I am also a little worried because I have heard that getting Botox can make facial expressions look unnatural. I am curious if it is actually possible to feel an unnatural or stiff sensation when smiling after receiving the injection. I would also like to know if the timing of the Botox's effects appearing and the duration of its maintenance vary from person to person.

I’ve heard that nowadays people get Botox not only for the jaw but also for various other areas like the forehead, glabella, and calves. I’m curious if the effects of Botox vary depending on the area. In particular, I’ve heard that jaw Botox is effective for improving a square jaw, so I’d like to hear from those who have actually experienced dramatic changes.

I am also curious to know what factors should be considered most important if this is my first time getting Botox. I have heard that the effects can vary significantly depending on the clinic and the dosage, so please let me know if there are any guidelines that a beginner should keep in mind. I would also like to know about any essential points or precautions I need to be aware of before getting the injection.