In Vivo: Definition and Applications in Cosmetic Testing

What Does In Vivo Mean?

In vivo means “within the living” and describes studies performed in a living organism rather than in an isolated laboratory system.

In cosmetic research, in vivo testing may involve controlled studies with human volunteers to assess characteristics such as skin hydration, skin elasticity, transepidermal water loss (TEWL), product efficacy or skin tolerability.

In Vivo Methods in Cosmetics

In vivo studies can provide information about how a cosmetic product performs under conditions that more closely represent its intended use. Depending on the study design, measurements may be taken before and after product application and compared with baseline or control measurements.

Examples include studies evaluating:

• Skin hydration
• Skin barrier properties
• Skin elasticity
• TEWL
• Appearance of fine lines and wrinkles
• Product tolerability

In Vivo vs. In Vitro

The main difference is where the study is performed:

• In vivo: within a living organism, such as a human volunteer.
• In vitro: outside a living organism, using isolated cells, tissues or other biological materials.

Both approaches can provide useful information, and the appropriate method depends on the specific objective of the study.