Twenty years ago, the effect of botulinum toxin injections lasted five to six months. Today it rarely exceeds three. When injections that were initially effective gradually lose their potency, this is called secondary resistance. It develops when, over a course of repeated injections, the body builds antibodies against certain proteins in the product and neutralises the toxin.
In a 2022 study of 469 dermatologists in South Korea, roughly half reported seeing clinically meaningful resistance in patients they had treated with botulinum toxin.
Why botox effectiveness can fade
Of course, a drop in effectiveness can have many causes besides true immunological resistance. The most common contributing factors are:
- Frequent touch-ups — adding extra doses within one to two weeks of the original treatment.
- High doses — using more units than necessary at each application.
- Too-frequent treatment — repeating an application before the previous effect has fully worn off.
- Improper cold-chain storage of the product.
- Injection into the wrong site.
- Insufficient dose.
- Incorrect injection technique.
- A congenital resistance to botulinum toxin.
- Changes in the product's formulation.
When the effect and duration of botox decline over time despite all of these factors being controlled, it suggests the body has developed resistance to that particular brand. This resistance does not necessarily occur through antibodies. Three factors are thought to make immunological resistance more likely: high doses at each session, treatment intervals that are too short, and supplemental doses given soon after the initial application.
Botulinum toxin types
If resistance develops, the best solution is often to switch to a different botulinum toxin brand. There are seven known types of botulinum toxin (A, B, C, D, E, F, G), but only the first two are used as medicines. The ones used cosmetically are type A toxins. Of the four FDA-approved type A toxins, three are licensed in Turkey:
- Botox Cosmetic® (onabotulinumtoxinA)
- Dysport® (abobotulinumtoxinA)
- Nabota® (prabotulinumtoxinA)
Although these brands differ in dosing, spread, onset and duration, they generally deliver the same clinical result. They are produced by different manufacturers: Botox® by Allergan, Dysport® by Ipsen, and Nabota® by Daewoong.
A note on Nabota®
Nabota® is the newest botulinum toxin introduced to the Turkish market. It is of Asian origin, has long been used worldwide and carries FDA approval. It is produced in a single factory in South Korea and marketed globally under different names (in the United States it is sold as Jeuveau®). Its indications are the same as the other botulinum toxins available in Turkey. Its diffusion is more limited, its onset is faster, and its overall clinical duration is somewhat longer. Like the others, it still requires cold-chain storage.
