I didn’t know that. All I know was that for my entire childhood, there was this crumpled tube covered with sticky black fingerprints in the family medicine cabinet. I still don’t know how efficacious ichthyol is, but as a blaring advertisement, “Look here! There’s a huge zit underneath this glob of black gunk,” nothing beats ichthyol! Try to identify from their chemical formulae these other home remedies that might be lurking in your medicine chest.
ZnO + Fe2O3
(CH2)n 20 ≤ n ≤ 40
KAl(SO4)2 + 12(H2O)
C23H46N6O13 + (H2SO4)3, C56H100N16O17S, C66H101N17SZn
Bernhardt MS. Better Living Through Chemistry. JAMA Dermatol. 2013;149(9):1016. doi:10.1001/jamadermatol.2013.4213