The phrase "human volunteers" refers to people who willingly offer their time and effort to help with a specific task or project, without expecting any form of payment or reward. Full definition
Studies in human volunteers come in 3 main steps, or phases. (hvtn.org)
Our products are tested on a panel of human volunteers who have sensitive and allergy - prone skin. (odylique.com)
The antioxidant activity of the extract was assessed and both formulations were tested on 13 human volunteers for 3 months. (supernaturalacnetreatment.com)