U.S. scientists who challenged a new rule that would require them to register their basic studies of the human brain and behavior in a federal database of clinical trials have won another reprieve. The National Institutes of Health (NIH) in Bethesda, Maryland, says it now understands why some of that kind of research won’t easily fit the format of ClinicalTrials.gov, and the agency has delayed the reporting requirements for another 2 years.

The controversy dates back to 2017, when behavioral and cognitive researchers realized that new requirements for registering and reporting results from NIH-funded clinical studies would also cover even basic studies of human subjects, experiments that did not test drugs or other potential treatments. The scientists protested that including such studies would confuse the public and create burdensome, unnecessary paperwork. A year ago, NIH announced it would delay the requirement until September and seek further input.

The responses prompted NIH staff to examine published papers from scientists conducting basic research. They agreed it would be hard to include some of these studies into the rigid informational format used by ClinicalTrials.gov—for example, because the authors didn’t specify the outcome they expected before the study began, or they reported results for individuals and not the whole group. In other cases, the authors did several preliminary studies to help them design their experiment.

Because ClinicalTrials.gov asks for prespecified outcomes and aggregate results, the reporting requirement “might not communicate what the studies planned to do, or was done, in a scientifically meaningful and useful manner,” NIH officials conceded in a blog post today . NIH is, therefore, delaying the rule that basic studies that qualify as clinical trials be registered in ClinicalTrials.gov until 24 September 2021 so the agency can explore other ways to report the research. (However, in the interim, such studies must still be registered and results reported in a publicly available “alternative platform.” Although NIH isn’t specifying those platforms, one example is the Open Science Framework , an NIH spokesperson said.)

The agency has not backed down from classifying many basic research studies with humans as clinical trials. “But it seems to essentially be saying that NIH knows that relabeling basic research as clinical trials won’t work,” says Sarah Brookhart, executive director of the Association for Psychological Science in Washington, D.C. “My hope is they are now willing to work with the community to figure out the best ways to achieve our shared goal of providing access to the research in question,” she says.

*Clarification, 25 July, 1:05 p.m.: This article has been revised to indicate that even though NIH is delaying a requirement that certain studies be registered in ClinicalTrials.gov, investigators will still need to register the studies and report results on a public platform.