Every trial has a list of eligibility criteria that outlines who will be suitable (or eligible) to take part. You may see this list referred to as the “Inclusion/Exclusion Criteria”. These lists are important for the safety of the volunteers, and reliability of the data from the trial.
The clinical trial registers available online will usually list the main trial inclusion/exclusion criteria. However, only the researchers will be able to make the final decision as to whether you are eligible after reviewing your health and screening test results against the inclusion/exclusion criteria. The research can only perform this review after they have explained the trial and you have decided to consent (agree) to take part.