Mammoth Uncensored Word List:
60 words ending with in, 12 letters long

anthoxanthin antiglobulin antithrombin betweenbrain carragheenin catamountain chlorohydrin chloropicrin chromogranin chrondroitin chymotrypsin concanavalin counterstain cryoglobulin cyclodextrin cytochalasin daunorubicin erythromycin featherbrain fibrinolysin flavoprotein geoporphyrin glucoprotein glycoprotein gonadotropin griseofulvin haematoxylin indomethacin isotretinoin lactoprotein luteotrophin lysolecithin melanotropin multivitamin neurotrophin noradrenalin oleandomycin oleomargarin pancreozymin phaeomelanin phenylalanin phycoxanthin physostigmin plastocyanin porphyropsin prostacyclin pyrocatechin scatterbrain siderophilin somatostatin somatotropin streptolysin streptomycin strophanthin superaspirin tetrodotoxin thyrotrophin tryptoflavin turacoverdin xanthopterin