Neurotoxins are biological substances that interfere with neural transmission. Neurotoxins are also known as neuromodulators. In this course, we will specifically be talking about Type A Botulinum Toxins. These toxins are produced by the bacterium Clostridium botulinum-the bacterium responsible for botulism. Type A Botulinum Toxins are peptides composed of one heavy chain and one light chain; these toxins block the release of acetylcholine, the principal neurotransmitter at the neuromuscular junction, causing muscle paralysis. It is the inhibition of neurotransmission between peripheral nerve endings and muscle fibers that weaken or paralyze the skeletal muscle.

In the world of aesthetics, type A botulinum toxins are used in small doses to weaken facial, chin, neck, and chest muscles to prevent wrinkles, fine lines and signs of aging.

The brands that are FDA approved in the United States include: Botox, Xeomin, Dysport and Jeuveau with Daxi pending FDA approval.