in vivo

American  

[in vee-voh] / ɪn ˈvi voʊ /

adverb

1. (of a biological process) occurring or made to occur within a living organism or natural setting.

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in vivo British  

/ ɪn ˈviːvəʊ /

adverb

1. (of biological processes or experiments) occurring or carried out in the living organism

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in vivo Scientific  

/ ĭnvē′vō /

1. Inside a living organism.

2. Compare in vitro

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in vivo Cultural  

1. In nature; literally, “in life.” In vivo conditions are distinguished from those that might exist only in a laboratory. (Compare in vitro.)

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Etymology

Origin of in vivo

First recorded in 1900–05; from Latin in vīvō “in (something) alive”

Compare meaning

How does in-vivo compare to similar and commonly confused words? Explore the most common comparisons:

• in vivo vs. in vitro

Example Sentences

After completing the in vivo study, the research team closely examined liver tissue from the mice.

From Science Daily • May 9, 2026

Earlier studies have linked them to a range of biological effects, including antifungal and anticancer activity observed both in vitro and in vivo.

From Science Daily • May 7, 2026

That includes $6.3 billion upfront for Centessa Pharmaceuticals, which is developing treatments for sleep disorders, and $3.25 billion upfront for in vivo CAR-T developer Kelonia Therapeutics.

From MarketWatch • Apr. 30, 2026

Orna Therapeutics develops RNA drugs and a cell therapy for autoimmune diseases using in vivo CAR-T technology.

From Barron's • Feb. 9, 2026

In this case then the condition of the blood in vivo is satisfactorily explained by the absence of function of bone-marrow.

From Histology of the Blood Normal and Pathological by Myers, W.