Tetrodotoxin　(TTX)　is　a　dangerous　neurotoxin,　where　its　toxicity　is　due　to　its　highly　specific　binding　and　inhibition　of　sodium　ion　channels.　Because　the　blocking　sodium　ion　channels　could　inhibit　the　transmission　of　pain,　TTX　is　a　candidate　for　an　anesthetic　drug.　Trials　on　rats　and　humans　have　shown　that　TTX　has　anesthetic　ability　with　minimal　adverse　effects　under　6　μg/Kg.　It　has　short　therapeutic　window,　but　it　is　still　a　promising　substitute　of　morphine.　The　performance　could　be　improved　with　modifications　such　as　covalent　conjugation　with　a　biodegradable　polymer,　combination　with　other　chemicals　such　as,　chemical　permeation　enhancers,　epinephrine,　or　a　low　dose　of　morphine　alone.　©　2023　SPIE.