Neurotoxin injections continue to reign supreme as one of the top minimally invasive procedure, according to the American Society of Plastic Surgeons’ yearly statistical report. In fact, the report shows that the popularity of neurotoxin injections rose by four percent, which is no surprise, considering that the treatment has become, for many people, as routine as a twice-yearly teeth cleaning.
With more and more people visiting their injectors to keep up with appearances, it’s become somewhat commonplace for patients to be experiencing what they think is neurotoxin resistance. In other words, patients are reporting that their toxin has seemingly stopped working—but the conversation is a little more nuanced than that. Ahead, we break down what neurotoxin resistance is, why it’s not as common as you think and why Xeomin can be a great option for those who truly suspect they have developed resistance.
Featured experts
- Dr. Shereen Teymour is a board-certified dermatologist in New York
- Janine Hopkins, MD is a board-certified dermatologists in Southlake, TX
What is neurotoxin resistance?
Neurotoxin resistance is a phenomenon that explains a patient’s “diminished or absent response to botulinum toxin treatments despite receiving the appropriate dose, proper injection technique and treatment in the correct muscles,” explains New York dermatologist Dr. Shereen Teymour. True neurotoxin resistance occurs when the body develops neutralizing antibodies that reduce the effectiveness of botulinum toxin. Fortunately, true biological resistance is quite uncommon, only occurring in about 0.5 percent of patients, according to a study.
How can neurotoxin resistance occur?
“Repeated exposure to any biologic protein has the potential to stimulate an immune response,” says Southlake, TX dermatologist Janine Hopkins, MD. However, clinically significant resistance is very rare in aesthetic practice, particularly because cosmetic doses are relatively low with treatment spaced several months apart. True neurotoxin resistance is thought to occur when the immune system develops neutralizing antibodies that bind to the active botulinum toxin and prevent it from working effectively.
“Historically, higher protein loads and frequent high-dose treatments were thought to increase this risk, although today’s commercially available toxins have a very low incidence of antibody formation,” says Dr. Hopkins. More often than not, perceived neurotoxin resistance is simply “a reduced response related to factors like muscle adaptation, changes in anatomy, dosing, injection technique or simply progression of the aging process rather than true resistance,” says Dr. Teymour.
That said, there are still several factors that may increase your theoretical risk of antibody formation, including frequent treatment, very high cumulative doses or receiving “touch-up” injections too soon after your initial treatment. “There has also been discussion that accessory proteins, sometimes called complexing proteins, present in some formulations could contribute to immunogenicity, although the overall clinical significance remains an area of ongoing research. Regardless, clinically meaningful resistance remains uncommon in cosmetic dermatology,” says Dr. Teymour.
Can Xeomin help those with true neurotoxin resistance?
Dr. Teymour says that Xeomin is often considered a reasonable option when there is a concern for immunologic resistance because “it contains only the purified 150-kDa botulinum toxin molecule and does not contain the accessory (complexing) proteins found in some other botulinum toxin formulations. For this reason, Xeomin is sometimes referred to as a ‘naked’ neurotoxin.”
Theoretically speaking, reducing unnecessary protein exposure with a neurotoxin like Xeomin may potentially lower the risk of stimulating an immune response for those who are clinically resistant. “Though reducing unnecessary bacterial proteins may reduce the overall antigenic exposure, definitive evidence that this translates into lower rates of clinically significant resistance in aesthetic patients is still evolving,” says Dr. Teymour. She further explains that if a patient has in fact developed antibodies against the accessory proteins rather than the neurotoxin itself, some clinicians have reported improved responses after switching to Xeomin.
“In practice, Xeomin is an excellent option for patients who are concerned about minimizing unnecessary proteins, with many experts favoring it for patients with suspected resistance, but it’s important to remember that true antibody-mediated resistance is rare,” notes Dr. Teymour.
