Botulinum toxin 100iuBotulinum toxin is a substance that scientists study because it comes from a bacteria called *Clostridium botulinum*. Its a powerful protein that can block signals from nerves to muscles, making muscles relax. Researchers are interested in it because its used in tiny amounts to understand how nerves and muscles work together. In lab research, Botulinum toxin, often in a 100 international unit (iu) dose, is explored for its effects on muscle movement