Botox On Cupid's Bow Area?

If botox caused a temporary muscular imbalance of the perioral area, it should resolve as the Botox wears off and thereafter as the relaxed muscle awakens and becomes stronger. If concurrent treatment with fillers was rendered, then possibly a long lasting filler was used that caused the effect described. See a board-certified dermatologist or plastic surgeon.

The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice.  The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs.

It is very difficult to answer your question without seeing your pictures-you should consider posting images showing that area. Botox placed in the upper lip would relax the muscle around your mouth and/or lips, and wear off in 3-4 months.

First of all, Botox is rarely put into cupids bow, but when botox is used in the upper lip, it is often installed in low doses across the upper lip, outside the philtral ridge area to minimize the appearance of fine lines above the upper lip that often come with age. 

If the botox was injected over 6 months ago, it is no longer actively affecting the movement of any muscle no matter where it was injected or the quantity. What you are experiencing at this point in your life is loss of philtral ridge volume, (the 2 cute little vertical lines between the base of your nose and the upper lip) which is normal with the aging face, and the solution is to use hyaluronic acids (Juvederm or Restylane) to volumize the philtral ridges.

Consult a board certified dermatologist or plastic surgeon if you are unhappy with the appearance of your lips.