There are several brands of botulinum toxins available for medical and and a couple for cosmetic practice. Botox is of course the most well known. The toxin was isolated in the late 1800's after an outbreak of food poisoning from sausage in Germany. They eventually identified the bacteria Clostridium Botulinum. The word botulus actually means sausage. The toxin is taken into the nerve ending that attach to the muscle and block the release of the chemical acetylcholine which activates muscle contraction. This relaxes the muscle and reduces active movement in the face and thereby decreases dynamic wrinkles. In 15+ years of practice using Botulinum Toxins both medically and more recently in cosmetic work, I'd say the average onset of action is 2-5 days with increased and peak effects in a couple weeks. The vast majority of my patients over the years note effects starting to wear off at around the 10-12 week mark.
