It might be. An example? If we take the case of a drug trial of phase 1, the medicine you will be testing will be meant to cure an illness of which you don’t suffer. Therefore, you will not benefit from the experience. However, during the recruitment procedure or the follow up visits, diagnostic examinations (blood tests or magnetic resonance imaging, for example) might be undertaken. Besides, being useful for the experience, they might detect a disorder you might suffer from.

As for the clinical trials, they might allow some sick patients to be the first beneficiary of promising treatments.