The scientists at the Italian National Research Council's Institute of Neuroscience in Pisa injected the toxin into the whisker muscles of rats and found traces of it were evident in the rodents' brain stems three days later and was still present six months later.
It works by weakening or paralyzing muscles or blocking nerves to smooth out the skin and the effects last for up to four months.
Botox can cause side-effects such as headaches, an upset stomach or flu-like symptoms and there have been a significant number of reports of dangerous botulism symptoms in some users. Last month the Food and Drug Administration (FDA) in the U.S. warned that Botox and Myobloc caused severe muscle spasms in children with cerebral palsy, a use not approved by the FDA and some children had died
New warnings about the use of Botox....BD
Botox scare as scientists say the toxin may spread in the body