Botulinum toxin (BT) injections are commonly used to treat various cosmetic, muscular, anesthetic, and neurologic pathologies. In 2012, one study suggested that a combination of zinc and phytase supplementation could increase the duration and degree of effects of botulinum neurotoxin type A (BoNTA). However, this study was met with scientific skepticism due to concerns of financial conflicts of interest, unmasking the study too early, and ambiguity of the dosage of zinc used. In 2021, a new study with 25 patients receiving BoNTA injections for the treatment of excessive gingival display (EGD), showed that zinc supplementation prolonged the effect of BoNTA with statistical significance. There has been no further studies or commentary since these latest results were published. The purpose of this study is to test if the effect of zinc supplementation on BoNTA can be replicated and also translated to a different disease process that is also treated with BT-spasmodic dysphonia (SD). If positive effects are discovered, this would strengthen the preliminary results of the 2021 study, encourage future larger studies on the same hypothesis, and, ultimately, could lead to reducing the burden of disease for patients with SD and any other condition that is treated with BT injections.
