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

The order also called on the Drug Enforcement Agency to create a system for allowing patients to access investigational psychedelic drugs under regulatory review. —Alex Harring, CNBC, 20 Apr. 2026

The film shows Dane's desire for the reauthorization of the ACT for ALS, a 2021 law which grants funding to scientific research and expands access to investigational ALS treatments for people who are not otherwise eligible for clinical trials. —Anthony Robledo, USA Today, 10 Apr. 2026

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

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