In our cosmetics practice, a is common to hear patients asking about ‘Botox’ (botulism toxin A) injections – for everything from a sagging chin to a droopy eyelid. In some cases, our patients are impressed with just what these injections can do for them, and at other times we have to direct them to another treatment, or teach them about some of the limitations seen in this treatment. One thing is clear: the information available for these procedures seems to be limited, and sometimes conflicting.
One has to wonder just what it is that injections like Botox/Dysport/Xeomin does and how exactly does it work? 
Let’s go for a quick science lesson:
Botulinum toxin A, the active ingredient, was first researched back in the 1960s. Originally the purpose of this was to treat neurological disorders.  In 1989 Botox was finally approved by the FDA to treat eye muscle disorders like blepharospasm, uncontrollable blinking, strabismus, crossed eyes and even wrinkles.  In the year 2000 it was approved to treat cervical dystonia.  This is a disorder that causes severe neck and shoulder contractions and also a very unusual side effect of eye disorder treatments.  In their research, doctors discovered that the injections softened the frown lines between the eyebrows.  It was after this discovery that Botox officially came into existence and was FDA approved on April 15, 2002. 
Botox/Dysport/Xeomin injections themselves are actually a diluted form of botulism, which in uncontrolled quantities can be dangerous or life threatening. Bodies like the FDA and Heatlh Canada make sure that commercially available product is safe for cosmetic use, and doesn’t cause enough paralysis to cause any serious damage.  
So how does this relate to wrinkling? Well, to put it simply, every time you laugh, smile, frown, or for that matter do just about anything with your facial muscles, wrinkles are caused by the underlying contractions of facial muscles.  After years of making these expressions the muscles start to become bulky, and lines between muscles start to become longlasting.  When these creases become permanent, no kind of skin cream can get rid of them. This is where botox comes in.  
So what exactly does Botox do? When Botox is injected into the muscles, it temporarily weakens neurochemicalimpulses which normally contract the muscles.  Because of this, over 2-3 weeks, frown lines start to get softer and in many cases eventually disappear completely.  Botox can be injected into the muscles of the face that cause crows feet, forehead lines and frown lines. This givens a refreshed, energized, and more youthful appearance.
The art of these injections is in injecting just enough for the frowns to disappear, but just enough to still maintain to maintain a natural, dynamic, and expressive face.