Neurotoxin: A Primer on Botox, Dysport, and Xeomin

Neurotoxin Example Photo

Neurotoxin: A Primer on Botox, Dysport, and Xeomin


What is a neurotoxin? 


Neurotoxins in the aesthetic world are formulations of botulinum toxin that are typically injected into the facial muscles to relax the muscles and smooth wrinkles. Neurotoxin injection is the most frequently performed cosmetic procedure in the US and offers predictable results with few side effects and high patient satisfaction. There are several different brands sold commercially, including Botox, Dysport, and Xeomin. 


Botulinum toxin is derived from the Clostridium botulinum bacterium and inhibits the release of acetylcholine at the neuromuscular junctions between nerves and muscles, which causes localized relaxation of the muscles within 2 weeks that can last 3-4 months. Neurotoxins have a more dramatic effect on dynamic wrinkles, which are only seen during muscle contraction (smiling), compared to static wrinkles, which are seen at rest. Wrinkles form because of dermal atrophy (loss of collagen and elastin in the skin) and repetitive contractions of underlying facial musculature. 


What are neurotoxins used to treat?


The FDA has approved the use of neurotoxins for the treatment of frown lines (glabellar lines) and crow’s feet, although other areas of the face and neck can be treated effectively including forehead wrinkles, peroral lines, platysmal bands, and horizontal neck lines. Neurotoxins can be injected into the masseter muscles to reduce grinding at night and slim the face because the muscles atrophy or shrink over time. For patients with migraines, neurotoxins can be injected into the muscles of the head and neck as a treatment. Neurotoxins can also be used to treat hyperhidrosis, which is excessive sweating from areas like the armpits and palms by blocking the signal between nerves and sweat glands. Several additional less common indications for neurotoxin include blepharospasm (blinking or twitching of the eyelid that can’t be controlled), strabismus, cervical dystonia, and overactive bladder. 


What are the differences between the neurotoxins?


Botox, Dysport and Xeomin all use Botulinum toxin serotype A, which is the most potent serotype.  These neurotoxins differ in whether they have complexing proteins surrounding the core neurotoxin. Xeomin is the only one of the three that does not have a complexing protein.  These neurotoxins are not interchangeable because they vary in their formulation, dosing, and clinical response. 


What are the injection reactions and complications of neurotoxin treatment? 


Injection reactions

  • Mild erythema, edema, and tenderness at the sites of injection are expected and resolve within a day.
  • Bruising is common and can range from pinpoint needle insertion marks to quarter-sized ecchymoses that can take up to two weeks to resolve. Ice and Arnica (plant supplement with anti-inflammatory properties) can be used to treat bruising.
  • Headaches can occur with facial neurotoxin injection and spontaneously resolve within a few days of treatment. 
  • Paresthesia or dysesthesia in the treatment area is rare and thought to be related to nerve trauma. 



  • Temporary blepharoptosis (drooping of the upper eyelid by 2-3 mm; reported rate of 1-5%) and eyebrow ptosis (descent of the eyebrow from its normal position) are rare complications of neurotoxin treatment and considered technique-dependent, meaning that these tend to happen more commonly with inexperienced injectors and incidence declines as skill improves.
  • Formation of antibodies to the neurotoxin, which can render treatments ineffective (reported rate of less than 1%).
  • Immediate hypersensitivity and allergic reactions are extremely rare and present with signs of urticaria, edema, and sometimes anaphylaxis


Neurotoxin injections are generally contraindicated in patients with keloid scarring, neuromuscular disorders such as myasthenia gravis, allergies to the constituents of botulinum toxin products, and body dysmorphic disorder.


What are the myths regarding neurotoxin treatments? 


  1. Different neurotoxins yield different results: There is no compelling evidence that one neurotoxin is more effective than the others. There are several low quality studies reported in the literature that demonstrate mixed results with numerous limitations. Any differences reported are more likely related to doses used and there is no formally accepted conversion rate between the products. 
  2. Diffusion profiles differ between the neurotoxins: spread of neurotoxin after injection refers to the relatively rapid physical movement of toxin from the original injection site, which is influenced by the injection technique including the volume injected, speed of injection, and angle of injection. Diffusion, however, refers to the relatively slow kinetic dispersion of toxin beyond the original injection site, which characterizes the toxin’s movement to receptors. Studies have shown that dose, not the type of neurotoxin, is the main driver of diffusion with higher doses diffusing into a larger area.  
  3. Protein load is clinically important: Some have suggested that complexing proteins with the botulinum toxin can limit the spread and diffusion of toxin from the target tissues. However, there is no clinical evidence that this is true. Moreover, it has been shown that neurotoxins with complexing proteins (Botox and Dysport) dissociate the complexing proteins when mixed in the vial, not injected into the skin. 
  4. Formation of antibodies are an important determinant of treatment failure in facial injections: The development of antibodies is comparable across the three different neurotoxins, ranging from 0-3%. Studies have shown that formation of antibodies is related to higher doses rather than type of neurotoxin. A study evaluating patients who were secondary nonresponders to neurotoxin treatments found antibodies in less than 50%, indicating that there are other factors contributing to non responsiveness over subsequent treatments. 
  5. Reconstitution solution matters: Studies have shown that reconstitution with preserved saline dramatically improves patient comfort without compromising efficacy (compared to preservative-free saline), whereas aggressive reconstitution may reduce efficacy. 
  6. Volume of injection matters: Different injectors use different dilutions that contain the same overall amount of neurotoxin, just with varying volumes of saline used for reconstitution. For example, one injector will dilute 6 units of Dysport into 0.1mL of saline, whereas another injector will dilute 6 units of Dysport into 0.3mL saline. Studies currently show that the amount of neurotoxin matters (6 units of Dysport), not the amount of saline used to reconstitute it (0.1 vs 0.3mL). 


Are injections of neurotoxin painful? 


Neurotoxin injections are performed using small-gauge needles (we use 31 gauge) to minimize discomfort and bruising.  Localized burning or stinging sensation during injection is commonly reported and resolves within a few minutes.There are maneuvers such as using a vibrator on the face during injection that can mitigate the sensations during injection.  The vast majority of patients do not need a topical anesthetic. 


What other treatments can be performed for static wrinkles? 





Neurotoxin injections are the leading nonsurgical cosmetic procedure worldwide with a high rate of efficacy and patient satisfaction. These injectable medications can be used to treat a variety of conditions, most commonly dynamic wrinkles of the face. There are several formulations of neurotoxin available without significant differences between the different types. At Studio R Aesthetics, all toxin injections are personally performed by Dr. Segura because she believes that the results achieved with toxins are greatly dependent upon the training, experience and skill of the person performing the injection. 


Shopping Cart