Please recommend an effective Botox product.

I tend to smile with my eyes a lot, so at some point, I started noticing about 3-4 lines of fine lines around my eyes. I am particularly concerned because the wrinkles look deeper whenever I smile.

I've been getting Botox on and off at a local place, but I haven't seen any effect, and it seems like it's getting deeper.

It seems a bit late, but I plan to start getting Botox regularly from now on.

Last time, with a certain product, I had a terrible headache for several days and barely managed to get through it by taking Tylenol.

After that, I was even more scared, so I avoided it.

Which Botox has few side effects and is effective?

Is it more effective to get it at intervals of a few months without headaches?

Please also let me know the duration.