Botulinum, the deadly toxin found in uncooked foods, is also a powerful muscle-relaxant, and tiny amounts of a purified form (Botox) are being injected into wrinkles to relax the surrounding muscles. It may benefit forehead and frown lines, crow’s feet, lower eyelids, lines on the side of the nose, and the area between the upper lip and the nose. It is also useful for treating involuntary muscle movements that can occur after a face-lift.
The injections need to be repeated every few months, since the effects wear off. The treatment decreases the ability to frown or squint and may cause the corners of the mouth to turn down. When used for areas around eyes, it produces a rounder appearance afterward, which patients should be aware of before they undertake the procedure.
The drug does not cross the blood-brain barrier, and, to date, the only side effects are temporary muscle weakness near the injection site. Although there have been some reports that Botox can reduce migraine and tension headaches, Botox also causes headaches in about 1% of cases. In some cases, the headaches can be very severe and long lasting (from eight days to a month). Some experts suggest that either a contaminated batch of Botox or a specific injection technique may be the cause, but additional investigation is needed.