How long does the effect of wrinkle-preventing Botox last?

I am receiving regular Botox treatments to prevent wrinkles caused by my habit of constantly frowning before it is too late.

On average, how long does the firmness usually last after receiving injections like Xeomin or Innotox?

I know everyone's constitution is different, but I am asking this question because I want to schedule my injections with proper intervals that are not too short to prevent developing resistance to Botox.

I am curious if Maypure verifies the authenticity of the product right in front of me, and I would also like to know in advance if there are any symptoms such as facial expressions becoming too unnatural or eyebrows rising after the Botox procedure.

I want to maintain my beauty without side effects for the duration of the Botox. I want to get Botox and be free from my wrinkle worries.