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

Clinical study recap The Langenhops enrolled in a clinical trial testing an investigational therapy developed by Rocket Pharmaceuticals. —Kerry Breen, CBS News, 27 Mar. 2026

Tivic emphasizes that the therapies remain investigational and are not approved for commercial use. —Lyssanoel Frater, USA Today, 25 Mar. 2026

Injectable aesthetic use is considered off-label/investigational and potentially contra-approved (opposite of approved use). —Cindy Krischer Goodman, Sun Sentinel, 5 Mar. 2026

Further compounding the issue is the astronomical cost of investigational product of research, driven upward over decades by escalating evidentiary standards, increasingly complex trial designs, and entrenched operational inefficiencies. —Elise Felicione, STAT, 26 Feb. 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