Synonyms of efficacious

efficacious

adjective

ˌe-fə-ˈkā-shəs 

as in efficient

producing or capable of producing a desired result

taking a cookie break while studying is one of the most efficacious ways of rejuvenating the mind that I have ever discovered

Synonyms & Similar Words

• efficient
• effective
• potent
• productive
• effectual
• adequate
• fruitful
• operative
• useful
• capable
• practical
• convincing
• practiced
• adept
• skilled
• proficient
• practised
• competent
• expert
• feasible
• skillful
• experienced
• practicable
• cogent
• useable
• valid
• accomplished
• realizable
• dynamic
• masterly
• active
• striking
• hyperefficient
• veteran
• workable
• telling
• ultraefficient
• killer
• functional
• usable
• applicable
• sound
• consummate
• versed
• virtuoso
• working

Antonyms & Near Antonyms

• ineffective
• useless
• inefficient
• ineffectual
• fruitless
• inoperative
• incapable
• unproductive
• counterproductive
• incompetent
• unskilled
• inexperienced
• futile
• vain
• unqualified
• unfruitful
• unsuccessful
• abortive
• empty
• hollow
• idle
• unprofitable
• worthless
• pointless
• unskillful
• inexpert
• inoperative
• unseasoned
• unavailing
• bootless

Synonym Chooser

How does the adjective efficacious contrast with its synonyms?

Some common synonyms of efficacious are effective, effectual, and efficient. While all these words mean "producing or capable of producing a result," efficacious suggests possession of a special quality or virtue that gives effective power.

a detergent that is efficacious in removing grease

When is effective a more appropriate choice than efficacious?

In some situations, the words effective and efficacious are roughly equivalent. However, effective stresses the actual production of or the power to produce an effect.

an effective rebuttal

When would effectual be a good substitute for efficacious?

Although the words effectual and efficacious have much in common, effectual suggests the accomplishment of a desired result especially as viewed after the fact.

the measures to stop the pilfering proved effectual

When can efficient be used instead of efficacious?

While the synonyms efficient and efficacious are close in meaning, efficient suggests an acting or a potential for action or use in such a way as to avoid loss or waste of energy in effecting, producing, or functioning.

an efficient small car

Example Sentences

Recent Examples of efficacious

Bernstein masterminded the specialty beauty retailer’s growth strategy, including a range of store openings, upgrades and remodels to existing doors, a focus on efficacious products as well as discovery via its program The Cache. —James Manso, Footwear News, 8 Sep. 2025

Appealing to such a wide demographic is quite unique, and might speak to why the brand resonates: an intentional focus on effortless and efficacious beauty, which is something many women look for regardless of their age. —Clara Ludmir, Forbes.com, 14 Aug. 2025

It-girl and clean beauty muse Hailey Bieber revealed recently that her simple yet efficacious eight-step routine includes one, too. —Conçetta Ciarlo, Vogue, 5 Aug. 2025

This intimate approach delivers highly bespoke and efficacious treatments. —Bea McMonagle, Forbes, 28 Feb. 2025

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