Although I neither enjoyed nor was I that good at writing, I was able to write a column by chance to talk about various topics regarding healthy skin. I want to show gratitude for the readers who enjoy reading my column.
After wondering what to write about, the topic I came up with is “botulinum toxin,” which we commonly refer to as “Botox.” Although Botox is used as a common noun, it is the name of the first commercialized products from Allergan’s botulinum toxin.
I chose Botox as the topic because I thought it would be meaningful to share some new information on Botox, which has recently been in the spotlight for multiple reasons, to readers as I have been studying by participating in clinical trials on square jaw Botox and Meso Botox since my time as a resident.
I will introduce the indications and side effects, tolerance, and the unscientific myths of botulinum toxin in a series of three columns.
Let's first look at the indications of botulinum toxin.
To identify the indications, it is necessary to know the mechanism of botulinum toxin. Botulinum toxin can irreversibly block all nerve endings processed through neurotransmission by acetylcholine.
First, because botulinum toxin can block nerve and muscle junctions, the familiar Botox procedure for removing wrinkles through the paralysis of facial muscles, is possible.
Besides, because neurotransmission of non-muscular structures such as salivary and sweat glands are also processed through acetylcholine, it is possible to reduce the enlarged salivary glands to make the facial outline beautiful or paralyze the sweat glands to prevent sweating.
Dermatological indications of Botox are wrinkles due to muscle (forehead, eye area, brow, and cobblestone chin), abnormal muscle tones (teeth grinding, asymmetric wrinkles), problems from muscles expanding (square jaw, calf muscle), salivary gland problems (parotid gland hypertrophy, submandibular gland hypertrophy), and sweat gland problems (hyperhidrosis). Plus, these are also used as indications at other medical departments such as rehabilitation medicine and urology.
However, will all the botulinum toxin you receive really work? Where will the ineffective toxin go?
First, not all botulinum toxin can be effective. Once injected into the muscle, most of the injection solution stays in the extracellular area and prepares to be absorbed into the nerves at the neuromuscular endings where it needs function.
In other words, only some of the solution is absorbed, and a part of them gets attached to the SNAP25 receptor (the receptor for the commonly used type A botulinum toxin). There is a high possibility that the amount of toxin exceeding the amount of receptor will be ineffective from the very beginning.
This is also most likely to be the reason why the “threshold effect,” where effects do not increase after reaching a certain amount of dose, often occurs. As a result, a significant amount eventually becomes ineffective and neutralized or absorbed throughout the entire body.
The half-life of the botulinum toxin in a tissue is known to be several hours, and almost no toxin remains at the injection site after two to three days, which means that it irreversibly blocks the SNAP25 receptor, fails to function, or becomes absorbed throughout the body.
The absorbed dose throughout the entire body dilutes in the blood, giving no serious effects on the body. Although there is no study on the lethal dose for humans, based on animal research, we can predict that problems can only arise if 30 bottles of 100 units of Botox are injected all at once. The theory is that toxins absorbed into the blood of the entire body are metabolized in the liver and thus inactivated.
To further increase the benefits of botulinum toxin, patients’ efforts are also required. In the next column, I will discuss in detail what to do and avoid after having a botulinum toxin treatment.