Preclinical Alzheimer's disease (AD), a newly proposed, actively researched, and hotly debated research-only diagnostic category, raises the prospect of an ethical dilemma: whether, and possibly how, to treat a disorder with no target symptoms. This proposed category rests on the detection of a number of biomarkers thought to provide evidence of AD pathophysiology years before any behavioral symptoms manifest. Faced with limited treatment options, patients and their relatives may come to consider complementary and alternative medicine (CAM) a viable option, albeit one with minimal supporting evidence. Accordingly, the hopes and needs of some preclinical patients and their relatives could further fuel market-oriented entrepreneurship for CAM. In this ethics review, we provide background and reflect on some ethical questions related to the roles of key stakeholders arising from the potential for CAM use in the context of a possible preclinical AD diagnosis.