Possible side effects include: transient headache, swelling, bruising, pain during injection, twitching, itching, numbness, asymmetry (unevenness), temporary drooping of eyelids or eyebrows. These side effects are rare, but have been reported. In a very small number of individuals, the injection does not work as satisfactorily or for as long as usual. Known significant risks have been disclosed, yet the theoretical risk of unknown complications does exist.
Botox® or Xeomin® are best at treating dynamic facial lines, those caused by facial muscle activity; lines present at rest mayor may not improve. A treatment may be effective for variable lengths of time with subsequent treatments, may not work as well or for as long as expected, or may not work at all. I have been informed of other alternatives which exist for the treatment of wrinkles such as topical creams, chemical peels, laser treatments, surgical removal of the frown muscles, forehead/brow lift, facelift, collagen or hyaluronic acid treatments.