effectual vs efficacious

effectual and efficacious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
effectual	No	Yes	No	No
efficacious	No	Yes	No	No

As adjectives, effectual and efficacious are synonyms defined as:

effectual and efficacious: producing or capable of producing an intended result or having a striking effect

Other synonyms of effectual include effective.

effectual (adjective)	efficacious (adjective)
producing or capable of producing an intended result or having a striking effect	marked by qualities giving the power to produce an intended effect
having legal efficacy or force	producing or capable of producing an intended result or having a striking effect