Zinc-dependent modulation of botulinum toxin type A efficacy: strategies for overcoming variability in therapeutic response in injection cosmetology

Background. Since its introduction, botulinum toxin type A has become an indispensable tool in aesthetic medicine, allowing not only the elimination of expression lines, but also the restoration of symmetry and correction of facial contours through the harmonious redistribution of muscle tone. Given the pace of modern life and patients' desire to maintain daily social activity, there is a growing need to optimize results and increase the duration of botulinum therapy. Among the possible solutions that could affect the effectiveness of neuromodulators, the elimination of local zinc deficiency is of particular interest. Zinc, acting as an indispensable cofactor of the light chain of botulinum toxin type A, not only stabilizes the structure of the toxin, but also dynamically supports its protease activity in presynaptic neurons. A local deficiency of this element can become a «hidden barrier» to achieving optimal aesthetic results. Recent studies reveal the dual role of zinc: in addition to its direct effect on the catalytic domain of BTA, it regulates many other processes that indirectly determine the rate of toxin elimination and the duration of the effect. However, traditional methods of correcting deficiency, such as oral supplementation, show conflicting results, highlighting the need for innovative solutions.

Results. This article systematizes data on the molecular mechanisms of zinc dependence of botulinum toxin type A, factors contributing to tissue deficiency of this trace element, and modern strategies for its correction. Particular attention is paid to clinical markers of hidden zinc deficiency relevant to everyday practice and the prospects for combined approaches combining highly purified botulinum toxin type A preparations with adjuvant zinc delivery methods. The results of the analysis are intended to revise the paradigm of preparing patients for botulinum therapy, making the correction of local zinc deficiency an important step in increasing the effectiveness and prolonging the aesthetic result. For cosmetic doctors, understanding these relationships is key to overcoming resistance, reducing the frequency of repeat procedures, and achieving lasting patient satisfaction-the most important criteria for success in modern aesthetic medicine.

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