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

Rubedo Life Sciences, a biotechnology company based in Mountain View, California, tested its investigational treatment, RLS-1496, in patients with eczema and other skin conditions. — Khloe Quill, FOXNews.com, 16 Oct. 2026

The release of clinical trial data for felzartamab, an investigational treatment for rare kidney diseases, could also lift shares of Biogen considerably, per JPMorgan. — Liz Napolitano, CNBC, 12 Oct. 2026

The Food and Drug Administration flagged a potential safety signal after four deaths were reported among patients with treatment-resistant schizophrenia who received investigational evenamide in clinical trials, MedPage Today informs us. — Ed Silverman, STAT, 9 Oct. 2026

Again, in thousands of patients with heart disease, the investigational medication fared no better than a placebo. — Adam Cohen, Oklahoman, 22 Sep. 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