Botulinum toxins are used for the cosmetic treatment of frown lines between and above the eyebrows, the forehead, and crow’s feet (the lines on the outer part of and beneath the eyes).  The three currently available brands, manufactured by different companies, are BOTOX® Cosmetic, XEOMIN®, and Dysport®.  The basic principle of the treatment is the same for each.  Wrinkles and folds of the face may be the result of muscle motion and/or tissue atrophy.  These injectable products reduce muscle motion and can result in dramatic softening or elimination of unwanted lines.   They accomplish this by temporarily blocking the release of a neurotransmitter called acetylcholine which is necessary to activate muscles.  The dosages are very dilute and localized to the area of desired effect.  The results typically last 3 to 4 months.