Long-term use of drugs containing semaglutide (Ozempic) and tirzepatide (Mounjaro) may reduce the durability of butrin type A toxin, according to research published in the journal Science Direct. The results showed that the effectiveness of Botox decreased from about 20 weeks to about 16 weeks.
The study involved a one-year computer simulation of 25,000 virtual patients. They simultaneously used a GLP-1 agonist drug, used to treat diabetes and obesity, and botulinum toxin type A (BoNT-A), which is used for both neurological (chronic migraine) and cosmetic indications.
The reductions varied depending on the type of substance used, with tirzepatide showing the strongest attenuation (results of 16.2 weeks) and semaglutide the least (results of 17.3 weeks).
Gustavo Novaes, a dermatologist and member of the SBD (Brazilian Society of Dermatology), said the study does not yet serve as clinical evidence, but it does serve as a warning and a lead for investigation.
The reduced effectiveness is caused by a decrease in lean body mass and changes in the way toxins act on nerve endings, the researchers said. Additionally, there are metabolic changes throughout the body.
SBD dermatologist Lauren Morais says this hypothesis is biologically plausible because the weight loss drug acts on the same protein (SNAP-25) as botulinum toxin.
According to the researchers, the next step in the study will be to analyze whether the results obtained so far using computer simulations are confirmed in humans. The first step is to test neuron cultures in the laboratory. If approved, the study will continue and patients will be followed for a long time.
Novaes also said it would be useful to note whether there is a shortening of effects in people using these drugs, “but there is still no scientific reason to change doses, intervals, or clinical management.”