The study involved seven human volunteers who had their large intestines removed.

Despite the success, using human volunteers to produce such a drug was considered impractical.

Even so, thousands of human volunteers will be needed to test its safety and efficacy.

Yet this advanced system needs human volunteers to run it.

This will be followed by a second, larger safety study in healthy human volunteers.

Lush tests its products on human volunteers before they are sold.

To some extent that's what happened with the three human volunteers who tried it.

We've fed them to animals and even to human volunteers.

Between 1964 and 1989, this bunker was used to conduct 418 studies in 447 human volunteers.

A clinical trial is a research study on human volunteers designed to answer specific health questions.