Chuck DarwinON JAN. 20, 2025, his first day back in office,
President Donald Trump signed an executive order declaring that the United States would henceforth recognize only two sexes, male and female.
Trump framed the move as one meant to protect the dignity, safety, and well-being of women. But the order also upended a long-standing policy at the National Institutes of Health
— one that was crafted to ensure that females are adequately represented in biomedical research.
Implemented a decade ago, the Sex as a Biological Variable policy, or #SABV, addressed an important shortcoming:
Evidence had shown that diseases and drugs can in some instances affect women and men differently,
yet scientists mostly used male animals in their preclinical lab experiments, leaving important questions about the effects on female bodies unanswered.
The NIH had grown increasingly concerned that male-only lab research wasn’t generating the data needed to inform clinical trials that include women.
The SABV set out to reverse this long-standing bias.
Developed with leadership from the NIH’s Office of Research on Women’s Health (ORWH)
and announced in 2015,
the policy directed federal funding applicants to explain how they were accounting for potential sex differences in preclinical research.
Applicants proposing to study just one sex had to provide clear rationales for why they were excluding the other.
And if proposal reviewers didn’t think the application adhered to the policy, then funding was less likely to be approved.
Applicants who had any questions about how to implement the policy could turn to the SABV’s webpage and the ORWH’s website for guidance.
The ORWH’s site had grown into an online resource packed with courses,
published papers,
and information on research methods relevant to sex differences,
-- and increasingly, gender differences as well.
Within days after Trump’s inauguration, the webpage that detailed the SABV policy suddenly read
“Access denied,”
sparking a panic that
the SABV “was just going to entirely be dissolved,”
said Rebecca Shansky,
a neuroscientist and chair of the Department of Psychology at Northeastern University who researches sex differences.
A short summary of the policy was later made available again on the ORWH’s website.
More than a year later, the ORWH doesn’t appear to have commented publicly about these changes.
And the resulting confusion has left some scientists concerned that following the policy could make them targets of the administration’s war against diversity, equity, and inclusion, or DEI, initiatives.
“Everyone who has over the last 10 years been trying to adhere to this policy is now saying,
‘Is adhering to the policy going to decrease my likelihood of getting funded?’” said Shansky.
Margaret McCarthy, a neuroscientist at the University of Maryland School of Medicine, models brain development in rodents as part of her research into sex-related differences in autism.
She said she has become more cautious about word choice in her NIH grant applications, hoping to avoid a rejection or a terminated research project.
Federal agencies have listed dozens of terms to avoid.
A list compiled by The New York Times includes the words
“female,” “females,” “gender,” “sex,” and “women”
— but, notably, not “males.”
“We’ve had no clear guidance on what is or isn’t in line with the administration’s priorities,” McCarthy said
https://undark.org/2026/03/30/sex-biological-variable/
charrvein
Danai Riga
Dr. Becca
Natalie Tronson