Epsom salts vs bitter salts

Epsom salts and bitter salts both are nouns.

Word	Noun	Adjective	Verb	Adverb
Epsom salts	Yes	No	No	No
bitter salts	Yes	No	No	No

As nouns, Epsom salts and bitter salts are synonyms defined as:

Epsom salts and bitter salts: hydrated magnesium sulfate that is taken orally to treat heartburn and constipation and injected to prevent seizures

Epsom salts (noun)	bitter salts (noun)
(used with a singular noun) hydrated magnesium sulfate used as a laxative	hydrated magnesium sulfate that is taken orally to treat heartburn and constipation and injected to prevent seizures
hydrated magnesium sulfate that is taken orally to treat heartburn and constipation and injected to prevent seizures