There's a thin line between an experimental treatment with some potential merit being trialed on vulnerable people, and a mad scientist just trying things "to see what will happen."

A lot of terminal people have, historically, had pretty terrible things done to them on the guise of "well they were going to die anyway!"

I for one welcome medical and academic oversight of experimental treatments. Terminal people are especially in need of protection as they will grasp to any hope no matter how slim or misguided.

The line is even thinner when it is some issue that impacts a persons ability to reason. An old person who is mentally all there can make an informed decision if they think the offered treatment is an actual attempt at a cure or some mad scientist's plaything, but someone with dementia is far less able to reason about such.

If you haven't seen it already, I highly recommend The Knick, a show about a doctor in the early 1900s, directed by Steven Soderbergh. It deals with these kind of issues.

An additional issue: While I am interested in an experimental drug and have no issues with its risk of death, my children / wife / family may choose to hold the drug liable in the case I die. I could make it as clear as possible that I would not hold the drug liable but if I die those words don't matter.