When people take part in medical research, they may undertake some risk of harm for the good of others. In response to serious abuses that took place in the past, ethical protections have been put in place to ensure that research participants are not exploited or put at unneeded risk. These protections ensure that participants know what to expect and are given the choice to participate or not. They also require researchers to treat individuals and groups fairly, and provide the greatest benefits to participants while making the risks as small as possible.
One protection that has been put in place is the informed consent process described above. Another is the creation of ethics boards that review research to make sure that the welfare, rights and privacy of participants are protected. Specific rules are in place to protect the rights of vulnerable groups of people such as prisoners or children.