Testing new medicines on people in return for money

We put this question to Shaykh ‘Abd-Allaah ibn
Jibreen (may Allaah preserve him, who answered as follows:

 If the harm which may result from this trial of
the new medicine can be treated with permissible (halaaal) medicine and
its effects can be lessened, whether this treatment is administered by the
drug company or by others, then it is OK for him to use the new medicine
in order to test it, whether this is done in return for money or
voluntarily. But if it is known that the medicine may have irreversible
harmful side effects which cannot be treated, then it is not permissible
for him to take it, even if a lot of money is offered in return, because
Allaah says (interpretation of the meaning): “And do not kill
yourselves” [al-Nisaa’ 4:29]. And Allaah knows best.