investigational

adjective

in·​ves·​ti·​ga·​tion·​al in-ˌve-stə-ˈgā-sh(ə-)nəl 

1

: of or relating to investigation

investigational activities

2

: relating to or being a drug or medical procedure that is not approved for general use but is under investigation in clinical trials regarding its safety and efficacy

an investigational new drug

Examples of investigational in a Sentence

Recent Examples on the Web

Shares of Merck have jumped 45% year to date as clinical trials for its investigational and experimental drugs continue to produce positive results. — Liz Napolitano, CNBC, 20 Aug. 2026

Recent reporting has found young people promoting and injecting purported Retatrutide on TikTok, despite its investigational status. — Emily Cegielski, Flow Space, 6 Aug. 2026

What comes next could be seen by some as a signal of how the FDA, which is under new leadership, weighs potential benefits and risks for investigational drugs. — Ed Silverman, STAT, 31 July 2026

On the mental health side, the agency issued priority reviews for promising psychedelic medications and oversaw the first investigational new drug clearance for a noribogaine compound. — Avik Roy, Forbes.com, 22 July 2026

Word History

First Known Use

1905, in the meaning defined at sense 1

Rhymes for investigational

• associational
• civilizational
• coeducational
• configurational
• consociational
• denominational
• improvisational
• organizational
• orientational
• preoperational
• representational
• aspirational