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

The company website shows Lilly is currently hiring for roles in its research division relating to in vivo pharmacology.

From Barron's • Feb. 9, 2026

The approach, known as in vivo CAR-T therapy, engineers a patient’s own immune cells to fight diseases inside the body.

From Barron's • Feb. 9, 2026

As the in vivo field expands from AAV therapies to lentiviral-vector-based therapies, those prices could fall sharply.

From The Wall Street Journal • Jan. 1, 2026

The new study uses in vivo experiments with mice infected with influenza viruses to shed light on how fever provides protection and why this protection may not be enough against avian strains.

From Science Daily • Nov. 28, 2025

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.