A study proposing to investigate the effects of medication after obtaining informed consent best illustrates what principle?

The principle being illustrated in the study proposing to investigate the effects of medication after obtaining informed consent is respect for persons. This principle emphasizes the importance of recognizing the autonomy and dignity of individuals involved in research. Obtaining informed consent is a fundamental aspect of this principle, as it requires researchers to provide potential participants with comprehensive information about the study, allowing them to make an informed decision regarding their participation. This process acknowledges the individual's right to make choices about their own lives and ensures that they are participating voluntarily and with full understanding of the risks and benefits involved.

Other principles such as justice, beneficence, and integrity play important roles in ethical research practices as well. However, justice focuses on the fair distribution of the benefits and burdens of research, beneficence emphasizes the obligation to minimize harm and maximize potential benefits, and integrity pertains to the honesty and transparency of the research process. While these principles are crucial to ethical research, the act of obtaining informed consent directly relates to the respect for persons, making it the correct answer in this scenario.