Despite its advantages, in vitro testing has several limitations. One of the main drawbacks is that it may not fully replicate the complexity of a living organism. Cells and tissues in vitro might behave differently compared to their behavior within an entire organism due to the lack of systemic interactions. This can lead to discrepancies between in vitro and in vivo results. Additionally, in vitro tests often use simplified models that might not account for the heterogeneity of human populations. For example, cancer cell lines used in vitro might not represent the diversity of cancer types found in patients. Hence, findings from in vitro studies need to be validated in more complex systems before they can be applied in clinical settings.
