Inefficacious antonyms

What is the opposite word for Inefficacious?

Antonyms for inefficacious
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Opposite words of inefficacious
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Antonyms for Inefficacious. (2016). Retrieved 2026, August 12, from https://thesaurus.plus/antonyms/inefficacious
Antonyms for Inefficacious. N.p., 2016. Web. 12 Aug. 2026. <https://thesaurus.plus/antonyms/inefficacious>.
Antonyms for Inefficacious. 2016. Accessed August 12, 2026. https://thesaurus.plus/antonyms/inefficacious.