thyroxine vs thyroxin

thyroxine and thyroxin both are nouns.

Word	Noun	Adjective	Verb	Adverb
thyroxine	Yes	No	No	No
thyroxin	Yes	No	No	No

As nouns, thyroxine and thyroxin are synonyms defined as:

thyroxine and thyroxin: hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells

Other synonyms of thyroxine include T, tetraiodothyronine.

thyroxine (noun)	thyroxin (noun)
hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells	hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells