Where trials are listed

One big list, in one place

When you go looking for a clinical trial, it helps to know that most of them live in a single, public place. In the United States, that place is ClinicalTrials.gov.

ClinicalTrials.gov is a registry — and that word is simpler than it sounds. A registry is just a public logbook. When researchers start a trial, they are required to write it down here so that anyone can look it up. The database holds hundreds of thousands of studies, in cancer and every other area of medicine.

It is run by the U.S. government, it is free, and you do not need an account to search it. Think of it as the official record of what trials exist and where.

The National Cancer Institute’s search

ClinicalTrials.gov covers all of medicine, which is a lot to wade through. If you want a view focused only on cancer, the National Cancer Institute (NCI) runs its own search.

The NCI search draws on the same underlying trial information but organizes it for cancer patients. You can narrow by cancer type, stage, and location, and the results come with plain-language summaries. For many people it is a gentler front door than the full government database.

What a registry does not do

Here is the honest limit of these databases: a registry lists trials, but it does not match you to one.

ClinicalTrials.gov and the NCI search will happily show you thousands of studies. What they will not do is look at your specific situation and say, “these three are the ones worth a closer look.” That sorting is left to you, your care team, or a tool built for the job.

That is not a flaw — a logbook is supposed to be complete, not opinionated. But it does explain why simply opening ClinicalTrials.gov can feel like drinking from a firehose.

Where a matching tool fits

Between the giant public list and your very specific situation, there is room for something in the middle: a matching tool.

A matching tool takes the same public trial information and helps sort it down — filtering out the studies that clearly do not apply and surfacing the ones that could fit you. It does not replace the registry; it sits on top of it and makes it easier to walk through. It also does not replace your doctor, who has the full picture of your health.

We are building one of these tools, and we cover how it works in how trialtree helps. For now, the map is simple: a big public registry holds every trial, the NCI search gives you a cancer-focused view of it, and a matching tool helps you find your way to the few that matter for you.