In Internet research:
Agent is aluminum chloride as in many other deodorants also, aluminum chloride is an acid and is considered a neurotoxin, is not harmful in this concentration. The aluminum chloride crystals are probably "narrow" the sweat glands or in forums make it also means "clog". So I wash my hands before applying the cream always make sure to thoroughly that no dirt or grease film, or other cream residues prevents the aluminum chloride crystals can enforce the pores and sweat glands.