In which phases must informed consent be written?

Informed consent must be obtained in writing primarily during Phase I and Phase II of clinical trials. During these phases, participants are often exposed to novel and untested treatments, and the risks associated with these treatments can be significant. Written informed consent ensures that the participants are fully aware of the nature of the study, possible risks and benefits, alternatives to participation, and their rights as participants.

In Phase I trials, the focus is on evaluating safety, dosage, and side effects of a new drug or treatment, which is crucial to ensure participants clearly understand what they are involved in. Similarly, in Phase II trials, where the effectiveness of the drug is beginning to be assessed, obtaining informed consent is essential for protecting participants as they may experience side effects and the study may involve more rigorous monitoring and interventions.

Phases III and IV generally involve broader analyses of the drug's efficacy and long-term effects, but the process for obtaining informed consent can differ since Phase III typically has more structured guidelines regarding participant information, and Phase IV often deals with post-marketing surveillance where standard informed consent practices continue, but they may not always need to be in written form. However, for the initial phases (I and II), a written consent is critical to ensure clarity and protection