A Hello, typically it takes botox 3-4 months to wear off. However, everyone reacts differently and can metabolize botox more quickly or slowly. If you have botox injected before it has completely worn off, you can cause a more "frozen" look and not be able to create the facial expressions you would like to. I would recommend waiting until your botox has worn off before having more injections. Address your concerns to your injector and they should be able to guide you down the right path :)
Best,
Caity