So first studies in man/woman are called phase I studies.
These are usually performed in healthy individuals in very well controlled environments, such as hospitals and usually specialise centres within the hospital setting so if things go wrong they are in the best place to deal with them. They are performed by specialist contract research organisations and they recruit volunteers for the study.
The people volunteering are often students and healthy males and they get paid for their time for volunteering, but they are all heroes or heroines.
It may be easy money if your drug, is safe like ours, but remember the "Elephant head" case where things went wrong. The gave a drug that was would cause white blood cells to grow like mad and release a lot of growth factors "cytokine storm" that caused the blood vessels to shut down causing loss of oxygen to the extremities and gangrene. Surprisingly, in toxicity studies this predicted problem was not seen, but animals like mice and rats are designed to live in dirty holes and tolerate all sorts of infections deal with "cytokine storms" humans can't.
Therefore we are grateful for to the brave people who take part in trials. Without these people things will never progress.
CoI We are developing a drug for people with MS