Researchers hope a steroid that shot to prominence during the Covid pandemic may help reduce blood loss in those who experience heavy periods.

The cheap anti-inflammatory dexamethasone was discovered to improve survival rates among patients critically ill with Covid. It is also used for conditions including severe asthma and certain forms of arthritis.

Now researchers say a small trial suggests dexamethasone helps to reduce the amount of blood lost among those who experience heavy menstrual bleeding – an experience studies suggest may affect 20% to 52% of menstruating UK women.

“Heavy menstrual bleeding can impact lives hugely, especially for particular employments or life circumstances,” said Dr Pamela Warner, a co-author of the research at the University of Edinburgh.

Another concern, she added, was the effect iron depletion as a result of excess menstrual bleeding could have on general health, particularly in countries with reduced access to universal health services.

“The most common [treatment] now by far is the IUS [intra-uterine system], which is also a contraceptive,” she said. While this also protects against pregnancy, it does not suit all women, particularly those who don’t wish to use synthetic versions of reproductive hormones, while it is also unsuitable for those trying for a baby.

It is hoped dexamethasone could provide an alternative.

Writing in the journal EBioMedicine, Warner and colleagues report how they examined data from 97 women over the age of 18 recruited to the study. All experienced heavy menstrual bleeding, with an average of 50ml or more blood lost across two measured periods, and regular periods that lasted 21 to 42 days.

The participants were randomised to either receive a placebo or one of six different doses of dexamethasone. These were taken twice a day for five days in the phase of their menstrual cycle before their period began. This was repeated for three menstrual cycles.

The results suggest that dexamethasone might reduce the volume of blood lost during periods, although the greatest and most clear-cut effect was seen for the highest dose of 1.8mg of dexamethasone a day. After taking into account the measured levels of menstrual blood loss at baseline, participants on this regime were estimated to have had an average reduction in menstrual blood loss of 25ml, compared with those on placebo – with the team 95% sure that the reduction is between 1ml and 49ml. The authors add those in this dosage group had a 19% average relative reduction in menstrual blood loss by volume compared with their individual baseline.

The team say the findings suggest dexamethasone could be a useful tool for tackling heavy menstrual bleeding.

“It is the first entirely new medical treatment for heavy menstrual bleeding for nearly 20 years,” said Warner, given that treatment launches in recent years have been developments of existing techniques.

She added that while three serious adverse events were recorded during the trial, none occurred among those who took dexamethasone, although there were some reports of mild potential side-effects such as dizziness, headache and sleep disturbance.

Warner said one option for future research may be to deliver the steroid via a self-applied vaginal pessary or other local method, which could mean a lower dose of dexamethasone would be needed – an approach that may also reduce side-effects.

The Royal College of Obstetricians and Gynaecologists (RCOG) said it welcomed any research into heavy menstrual bleeding but raised concerns about the small sample size of this particular study and that the potential long-term adverse effects were unknown. It called for a further trial with a more robust sample size.

However, Dr Annalise Weckesser, a medical anthropologist with expertise on gender and reproductive health at Birmingham City University, and who was not involved in the research, noted there is considerable overlap between those who live with heavy menstrual bleeding and those who live with endometriosis.

“For over two decades, those living with the highly disruptive and sometimes debilitating symptoms of heavy menstrual bleeding and/or endometriosis have reported that the limited treatments available are often ineffective or come with intolerable side-effects,” she said.

“While further research is needed on the use of dexamethasone to treat [heavy menstrual bleeding] given the dearth of treatment breakthroughs in women’s reproductive health generally, this is a welcome study that points to the possibility of a new non-hormonal and non-surgical treatment option.”