The Medical Research Council (MRC) has today published a report outlining how sex must be factored into all future research design. The hope is that this will enhance the translatability, reproducibility and novelty of scientific discovery.

The MRC London institute of Medical Sciences (LMS) has a history in shining a light on sex differences; Professor Irene Miguel-Aliaga, Professor Fisher, Professor Hajkova, Professor Festenstein and former institute member, Professor Brockdorff have all contributed to scientific discoveries showcasing how biological sex underpins differences in digestion, gut-brain communication, fertility, stem cell biology, development, genetic regulation and disease susceptibility. There is also a wealth of research showing drug and therapy effectiveness can differ between the sexes.

Professor Miguel-Aliaga, head of the LMS Gut Signalling and Metabolism research group was a member of the MRC working group who wrote the report. Commenting on its publication today, she says: “I am delighted to have contributed to this MRC working group. At the LMS we have shown sex differences impact on numerous biological and pathological processes. As such, it is important for discovery research to factor in both sexes because only then can we ensure anything translated into the clinic will work for both male and female patients. I am very pleased the MRC is taking a leading role in expecting both sexes to be included in grant applications – hopefully other funders will follow.”

Biological females represent half (50.6%) of the UK population, yet they are often overlooked in scientific research. The MRC found less than half (44%) of grant applications submitted to the council specify what sex of animal the researcher is planning to use. And of those who do specify the sex, a third (34%) plan to use only one.

A recent MRC survey found the vast majority of biomedical researchers utilising animal models (95%) or cell cultures (88%) saw the benefit in considering sex in their research. However, they expressed concerns about the number of animals this would require, the limited information available from commercial cell suppliers and an increase to research costs.

There was an ask for funding bodies to produce and disseminate clear guidance on how sex should be considered within research. In response to this, the MRC has agreed to forge a leading role to support and guide researchers to incorporate sex differences into their experimental design and research questions.

The MRC will soon expect both sexes being used as a default in all research. This will apply to the majority of human tissue, animal and cell-based research. Those who fail to recognise the importance of sex or to give robust justification for limiting their research to one sex likely see future grant applications rejected.

The council is aware some perceive grant applications to have a higher chance of success if the costs are kept low, and that this may have contributed to labs limiting their research to one sex. However, the MRC has stressed that they will fund studies if they are robustly designed, regardless of any increase in costs.

The MRC will be introducing these changes over the course of this year and they will be running a consultation to ascertain from researchers what they need to feel confident in addressing sex in their research.

Read more about Professor Miguel-Aliaga’s work at the LMS here, as well as a recent review she published discussing the importance of considering both sexes in research design.