hematin vs haem

hematin and haem both are nouns.

Word	Noun	Adjective	Verb	Adverb
hematin	Yes	No	No	No
haem	Yes	No	No	No

As nouns, hematin and haem are synonyms defined as:

hematin and haem: a complex red organic pigment containing iron and other atoms to which oxygen binds

Other synonyms of hematin include haemitin, heme, protoheme.

hematin (noun)	haem (noun)
a complex red organic pigment containing iron and other atoms to which oxygen binds	a complex red organic pigment containing iron and other atoms to which oxygen binds