Botulinum toxin works by inhibiting the release of a neurotransmitter, acetylcholine, by the nerve cells. This prevents the nerve signals from being released by the cells, and hence, neuromuscular blockage. Cilnically, what we see is reduced muscle movements- and reduction of dynamic wrinkles. The wrinkles are “erased”.
BOTOX: The First Approved Botulinum Toxin
In 2002, the USA FDA approved the use of BOTOX® Cosmetic to temporarily improve the appearance of moderate-to-severe frown lines between the eyebrows (glabellar lines). It ushered in a new era for medical aesthetics.
The second BoNT to be approved for the same purpose was Dysport, in 2009, followed by the 3rd, Xeomin, in 2011. Equivalence studies have shown that all 3 brands of BoNT work on reducing wrinkles. However, there are some significant differences between the 3.
BOTOX, DYSPORT, XEOMIN: Differences
BOTOX, Dysport and Xeomin all contain the same active ingredient: botulinum toxin type A. Numerous studies have been conducted to assess the properties of the 3 leading brands of BoNT, unfortunately, often with conflicting results. Here are some of them:
Onset: Dysport works the fastest1. Patients can feel its effects sometimes within 1 -2 days, and it also peaks faster. BOTOX starts working in 2-3 days, while Xeomin has a more gradual onset. Although it starts working in 1-3 days, patients feel the effects come on more gently. I experience the same in my clinical practice. However, all 3 BoNT brands reach their maximal effects in 2-3 weeks. BoNT also generally works faster in women than in men. Most of my patients prefer Xeomin as the onset is more gradual.
Strength: BoNT is measured in units. Numerous studies find that BOTOX and Xeomin are comparable in strength, with a conversion ratio of 1:1. Dysport, however, is measured differently. 1 unit of BOTOX/Xeomin is equivalent to 2.5-3 units of Dysport2.
Diffusion: The diffusion of BoNT is an important property as it determines how many injection points are needed. Spread of BoNT can also potentially lead to side effects such as ptosis of the eyelids. The scientific concensus is that there is no significant differences in spread between BOTOX, Dysport and Xeomin3.
Duration: There is, unfortunately, no clear proof of which brand of toxin lasts the longest. Most doctors will agree that BOTOX, DYSPORT and XEOMIN last 3- 6 months. One small study4 found that BOTOX may last longer than DYSPORT, but others disagree. A large study with 180 patients found that all 3 brands have a similar duration of action5.
Cost: In general, doctors charge less for Dysport and slightly higher for BOTOX and Xeomin.
Complexing Proteins: the BoNT in BOTOX and Dysport aare bound to complexing proteins. Xeomin, on the other hand, is unique in that during the manufacturing process, the complexing protains are removed to produce a “purer” form of BoNT. Complexing proteins may have a role in BoNT resistance, discussed in more detail below.
