Most readers have heard about the effectiveness of botulinum toxin. The effectiveness of botulinum toxin is achieved by interrupting the transmission of nerve signals to muscles, causing muscle paralysis and reducing the formation of wrinkles. There are two types of botulinum toxin used in medical aesthetics, Type A and Type B, with Type A further divided into three types, OnabotulinumtoxinA, IncobotulinumtoxinA, and AbobotulinumtoxinA, each with a different protein composition.
To understand the differences between the three types of botulinum toxin, one must first understand the chemical structure of botulinum toxin. Botulinum toxin produced and extracted by bacteria is composed of a core toxin and an accessory protein (see figure). The core toxin is what makes it toxic, while the accessory protein has no toxicity or pharmacological effects, so the clinical effect is mainly caused by the core toxin. The accessory protein protects the core toxin from being destroyed by external factors such as temperature or pH, which is important for the toxin to function properly in the body. The difference in the accessory protein of each type of botulinum toxin causes differences in their clinical effects.
The drug manufacturer first purifies the natural toxin into a powder form for doctors to use. This is what we see with Allergan’s Botox® (OnabotulinumtoxinA) and Dysport® (AbobotulinumtoxinA). Xeomin® (IncobotulinumtoxinA), the latest type of botulinum toxin, uses a special method to remove the accessory protein, becoming a “Naked Toxin.” In Hong Kong, these three types of botulinum toxin are currently the most widely used.
Do different brands of botulinum toxin have different effects? Xeomin®, which is more pure than other types of botulinum toxin, has clinical evidence of its effectiveness and has advantages over Botox® and Dysport® in certain aspects. One area that has been studied extensively is the issue of antibodies. In theory, the human body can produce antibodies against proteins, whether against the core toxin or the accessory protein. If antibodies are produced, they can render the botulinum toxin ineffective. Xeomin® has less accessory protein in its structure, reducing the chance of antibody production. However, people with muscle spasms who require frequent injections of large amounts of botulinum toxin have a higher chance of producing antibodies. In addition, Xeomin® has the advantage of producing faster results than the other two types. In one study, after injecting the frown lines, Xeomin® appeared to have a faster average effect time than the other two types by two days. For doctors, Xeomin® has the added benefits of being able to be stored at room temperature and having a longer shelf life. The emergence of new botulinum toxins is leading to new research and new opportunities in the botulinum toxin market.