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

Thanks in part to investigational therapies and ongoing research efforts, Roman, now 7, and Stella, now 6, have lived beyond the life expectancy given to them at diagnosis. —Tereza Shkurtaj, PEOPLE, 31 May 2026

Kailera said yesterday that its investigational obesity drug that targets three hormones led to significant weight loss in a Phase 1 study. —Elaine Chen, STAT, 27 May 2026

An investigational dementia drug may also ease alcohol withdrawal by calming the brain inflammation linked to addiction and relapse. —Melissa Rudy, FOXNews.com, 25 May 2026

And initial trial results are promising, according to BlueRock Therapeutics, the company behind the trial of the investigational cell therapy bemdaneprocel. —Michelle Marchante, Miami Herald, 30 Apr. 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