According to a new study comparing the effectiveness of Botox and Dysport in removing “crow’s feet,” Dysport was the hands-down winner.
The study, which compared the results of Botox and Dysport on the crow’s feet of 77 women and 13 men, found that patients preferred the results of Dysport two times out of three.
However, this was only when patients were asked to contract their facial muscles as hard as possible, since when faces were relaxed, there was no significant difference. The results were published in the journal Archives of Facial Plastic Surgery.
The results of the study have been challanged. Botox manufacturer Allergan, as well as some doctors, noted a number of possible flaws in the study, which include:
- Small sample size: 90 patients are very few in the grand scheme of statistics.
- Short length of the trial: the results were judged one month after the treatment.
- Dosing ratio: patients were treated with 10 units of Botox and 30 of Dysport.
Perhaps the most biting criticism of the study is Allergan’s assertion that “no two botulinum toxins are alike and each has a unique molecular structure, formulation, potency and safety profile… different botulinum toxin products are not interchangeable and no consistent dose ratio exists among botulinum toxin products.”
According to Dr. Doris Day, a dermatologist:
“there are variations in the reconstitution measures and final numbers of units used for each drug, and that can have a large impact on the final effect of the treatment. Because these are biologics, and because there are slight differences in the manufacturing process, there will be some differences in how the final product works.”
In other words, if you find that Botox works for you, it may be rash to abandon its use on the basis of a single study. It would be interesting, however, to see if the supposed advantage that Dysport holds over Botox for crow’s feet would appear in further studies with varied methodologies. As is often the case when discussing new studies, further research is needed.