In an article "Ethical Considerations in Leaping from Bench to Bedside" (Sugerman J; Science 285 : 2071, 1999) The author discusses "when it is safe and appropriate to initiate experimentation with human subjects." One passage is particularly illuminating:

"Early-phase clinical trials are designed primarily to answer scientific questions; benefit to individual research subjects are side benefits. For example, phase-1 studies in oncology are designed to test toxicity of experimental agents, and most subjects will not receive a dose that is expected to be in the therapeutic range. However, subjects may derive hope or meaning from the knowledge that they are contributing to scientific progress . . .."

Why would a sane individual want to participate in phase-1 clinical trials? To be poisoned by experimental agents? Or to get an inadequate treatment? And yet many do participate, since following the advice of their doctors. If you happen to be one of them look for another doctor with qualifications described in the section: "Doctors and Healers."