What is a clinical trial?
A clinical trial is a carefully designed research study that tests a new medicine, therapy, device, or procedure in human participants. Before any new treatment can be approved for general use, it must pass through clinical trials to demonstrate that it is both safe and effective.
Clinical trials are not experiments in the everyday sense of the word. They follow strict scientific and ethical rules, are overseen by independent ethics committees, and are regulated by government health authorities — in Hungary, by OGYÉI (the National Institute of Pharmacy and Nutrition).
Without clinical trials, no new treatment would ever reach patients. Every medicine that exists today went through this process.
Good to know: Clinical trial participation is always voluntary. You are never required to take part, and you can withdraw at any time without it affecting your usual medical care.
Why clinical trials matter
Clinical research is how medicine moves forward. It is also how patients sometimes gain early access to treatments that are not yet available through standard care.
- They produce the evidence that makes new treatments possible.
- They help doctors and researchers understand how a condition behaves in different people.
- Participants contribute directly to medical knowledge that may benefit future patients.
- Some participants receive close monitoring and care as part of the study process.
Participation does not guarantee a medical benefit to you personally. A clinical trial is a research study, not a treatment programme. Whether it is appropriate for your situation is something only a qualified study team can assess.
The phases of clinical trials
Clinical trials are conducted in stages called phases. Each phase has a different purpose and involves different numbers of participants.
A small group of participants — usually 20–100 — receives the treatment for the first time. The focus is on safety, dosage, and how the body responds.
A larger group tests whether the treatment works and what side effects may occur. Hundreds of participants may be involved.
The treatment is compared against an existing standard treatment or placebo in a large group — often thousands of participants across multiple countries. Required for regulatory approval.
After a treatment is approved, researchers continue monitoring its long-term safety and effectiveness in the general patient population.
Who can take part in a clinical trial?
Every clinical trial has its own eligibility criteria — a specific set of conditions that determine who can and cannot participate. These are called inclusion and exclusion criteria, and they are set by the study design and medical team.
Eligibility may depend on factors such as:
- Your medical condition and diagnosis
- Your age
- Previous or current treatments you have received
- Other health conditions you may have
- Your general physical condition and test results
- Where you live or which hospital you attend
Expressing interest in a clinical trial does not mean you will automatically be enrolled. Eligibility is always assessed by the study team at the investigative site, not by an external service.
If you do not meet the criteria for one study, it does not mean you will not qualify for another. Different trials look for different patient profiles.
What participation may involve
The experience of taking part in a clinical trial varies depending on the study. Before you formally enrol, the study team will explain everything in detail. Broadly, participation may include:
- Regular visits to the study site or hospital
- Medical examinations, blood tests, or scans
- Taking an investigational medicine or undergoing a procedure
- Keeping a diary or completing questionnaires
- Follow-up appointments after the active treatment period ends
Some trials are blinded — meaning you may not know whether you are receiving the new treatment or a placebo (an inactive substitute). This is a standard scientific method to ensure results are reliable, and the study team will explain whether this applies.
Possible benefits and risks
Deciding whether to consider a clinical trial involves understanding both what participation might offer and what it might involve.
Possible benefits
- Access to a new treatment before it is generally available
- Close monitoring and regular contact with a medical team
- Contributing to research that may help other patients in the future
Possible risks and limitations
- The new treatment may not be more effective than existing options
- You may experience side effects that are not yet fully understood
- You may receive a placebo rather than the active treatment
- Participation may require additional time and travel
Clinical trial participation does not guarantee a treatment benefit. It is important to discuss the specific study with your own doctor before making any decision.
Informed consent — what it means
Before you can formally join a clinical trial, the study team is required to provide you with full, clear information about the study — its purpose, procedures, risks, benefits, and your rights. This process is called informed consent.
You should receive a written informed consent form that explains everything in language you can understand. You have the right to take as much time as you need to read it, ask questions, and decide.
Signing an informed consent form is not a permanent commitment. You can withdraw from a study at any point — before it starts or after it has begun — without any penalty and without affecting your standard medical care.
Your rights as a participant
Clinical trial participants in Hungary are protected by both Hungarian law and EU regulation. Your core rights include:
You can leave a study at any time, for any reason, without needing to explain yourself. This will not affect the care you receive from your doctor.
You have the right to receive clear, complete information about the study before agreeing to take part. You may ask questions at any stage.
Your personal and health data must be handled with care, under EU GDPR and Hungarian data protection law. Your data cannot be shared without your consent.
If you withdraw or are unable to continue, your standard medical care continues unchanged. No trial participation should ever put your routine healthcare at risk.
Privacy and data protection
Clinical trials collect personal and health data. This is subject to strict rules under EU GDPR (General Data Protection Regulation) and applicable Hungarian regulations, which recognise health data as a special, sensitive category requiring heightened care.
Before any data is collected, you must be given clear information about: who is responsible for your data, what it will be used for, how long it will be kept, who it may be shared with, and what rights you have.
Your rights in relation to your data include the right to access it, correct it, have it deleted, or withdraw your consent at any time.
For information about how TrialSolve handles data, see our Privacy Notice →
Common questions
TrialSolve can help you understand the process and, where appropriate, connect you with relevant opportunities. There is no charge to patients, and no obligation when you express interest.