Yes, researchers can be subjects in their own studies. However, UMASS Amherst policy considers investigator self-experimentation as research with human participants, and generally requires the same review and approval as research that recruits other people as subjects.
Though investigator self-experimentation may not raise the conventional ethical concerns outlined in the Belmont Report, all human research projects should undergo ethical review to assure the safety of people involved and the integrity of the research at the university. While researchers may be aware of the risks of self-experimentation, they may also be more willing to accept risks that are ill-advised. Application for review with the IRB office allows a neutral third party to raise concerns and/or propose measures to promote the welfare of researchers.