The Botulinum toxin type A is a known substance and widely used in medicine since 1978 (ophthalmology, neurology) and since 1992 in medicine and cosmetic surgery. This substance injected into the muscle acts on the point of contact between nerve and muscle (neuromuscular plate) reducing and / or blocking the  muscle contraction. Then, after about 4-6 months, the plaque develops new neuromuscular synapses (connections) and the muscle begins to contract (see diagram). On the face is used to reduce until it stops, depending on the dose used, the contraction of facial muscles and thus to eliminate the so-called "expression lines."

TOXIN  EFFECT
 

NEW EYNAPSES

Very important for a natural result   is  studying  the  facial expressions of the individual patient, the force of  the  muscle contraction and any other asymmetries. Based on this it will mark the points where to inject the toxin, choosing the quantity and  the concentration. The next step will be to inject a few drops of product on the  muscle target  points , and after about 3-4 days, they will begin to appear the first effects  and   will be well established after 8-10 days.

Attenuation or elimination of frontal wrinkles and those annoying wrinkles  between the eyebrows (glabellar wrinkles): we can actually get a lifting effect of the 3rd top of the face. Also you can smooth out wrinkles around the eyes and have an opening of the look.
Contrary to the woman, the man's eyebrows  is parallel  to  the  arch  of the eyebrow bone. So  the Botox   must   never result in the raising of the tail of the eyebrow, so-called gull-wing, as it does in women

The results usually last six months; it was noticed that after several treatments the effect of smoothing lasts longer.

• Forehead   wrinkles 
• Wrinkles  between  the  eyebrows ( glabellar)
• Wrinkles around the eyes

Side effects are mainly related to the  used   technique  and then to   the operator's skill. One effect is to avoid the so-called "Mephistophelian "  appearance  that is  the   central  buckle of the eyebrows.

 Unnatural  Mephistophelian appearance

However, the most feared side effect is the lowering of the upper eyelid that can occur due to slipping of the toxin to the levator muscle of the eyelid when it is injected in the corrugator muscles located between the two eyebrows.
Clearly this is  a  reversible  effect , but it can  last   a few months.
Other side effects, if we can call  them  so, are related to the unnaturalness of the result, and then to asymmetries more or less accentuated.