Not dosing advice and not for human or animal administration
Studies involving acoustic and chemical insults show that growth factors represent a compelling class of otoprotective compounds (Yagi et al., The HGF mimetic Dihexa is a synthetically derived Angiotensin IV analog that is blood-brain barrier permeable, stable, and orally bioavailable (McCoy et al., in vitro and in vivo , making a strong case for a small molecule activator of HGF/c-Met to confer a neuroprotective benefit (Zhang et al., The experimental value of zebrafish as an animal model for in vivo drug discovery has grown rapidly due to their ease of assessment, large clutch size, and ability to recapitulate human disease conditions (MacRae and Peterson, in vivo , demonstrating that otoprotective drug discovery in zebrafish translates to mammalian systems (Owens et al., In this study, we demonstrate that Dihexa protects lateral line hair cells from aminoglycoside ototoxicity

However, before adding anything new to your regimen, though, consult your healthcare professional to make sure it is safe for you
In the case of Vitamin B12, more is not necessarily better