How long does the effect of Botox last?

I'm considering getting Botox because of my wrinkles,

I'm curious how long the effects of Botox last.

I wonder if it lasts a long time once you get hit,

Or I would also like to know if I have to get hit often.

I am especially curious about the effectiveness of Botox on forehead and frown lines.

Whether it improves naturally

Or I'm worried that there might be times when the facial expression becomes awkward.

Since it is my first time getting it, I would also like to know about side effects and precautions.

I would appreciate advice from those with experience!