Botox lip flip and upper lip weakness - Causes?

I'm sorry to hear of the issues from your Botox treatment. If you were spacing your treatments 3-4 months apart or more then this result is likely from the last treatment alone. Effects of Botox are temporary and you should notice improvement over the coming months I encourage you to discuss the concerns you have with your injector.

Hi there! Thank you for your question. I myself have experienced this, and what I can tell you, from personal experience both as an injector and as a patient, is that it happens sometimes, and sometimes it does not...even when you inject the same amount, in the same places.
While it can feel strange, some patients like this feeling because it reassures them that the Botox is working, while when they don't feel it, they assume nothing is happening. I don't necessarily think that this is the case.
Your best bet is to insure that your injector does the same amount and in the same pattern each time, so that you can replicate your results and experience as much as possible, although it is never a guarantee, as it can vary from one treatment to another. That said, try to stick with the same injector, as that will help with consistency of treatments as well.
The good thing about this situation is that Botox in the upper lip typically does not last very long, due to the constant movement of the mouth, so this odd feeling should wear off pretty quickly. Good luck!

Hi! Experiencing weakness in the upper lip post lip flip is extremely common. Your injector may have increased your dose, that could be why you didn't experience weakness initially. If I do 4units on a patient, they may experience no weakness, but if I inject 6-8units the weakness is normally guaranteed. Botox, or any neurotoxin injected is meant to weaken or "relax" that muscle, so you can expect it to do the same for the upper lip. I hope this helps!