Data on testosterone levels in women significantly outdated, finds report

Hertility, an Irish-founded UK and Irish healthcare provider for women, has released a groundbreaking study on female testosterone levels. The report, published in the Journal of Endocrinological Investigation, analyzed data from 30,453 women aged 18 to 74 who received at-home hormone testing in England, Scotland, and Wales between September 2020 and August 2025.

The findings reveal that testosterone levels decline steadily as women age, with no sudden hormonal drop often associated with perimenopause. Testosterone is essential for various bodily functions, including libido, mood, bone density, muscle mass, and metabolism. Despite its critical role, current testing methods rely on outdated data, drawing from just two small studies of 149 women in two age groups, 20 to 49 and over 50.

This reliance on outdated information can lead to false reassurance for some women while causing unnecessary investigation for others. The study suggests that hormone tests should be based on age-specific, continuous ranges rather than a one-size-fits-all approach. This would provide a more accurate representation of a woman's hormone levels within her specific age group, helping to avoid diagnostic delays that have long plagued women's health.

Experts emphasize the importance of precision medicine, which requires up-to-date, accurate reference ranges to ensure clinicians have the best possible information when interpreting hormone test results.