Researchers from China investigated what is happening around the hair follicles of women with pattern hair loss. In Female Pattern Hair Loss (FPHL), there is typically an even thinning of hair across the top of the head. As many with pattern hair loss will know, this can also come with sensations of tenderness or itching. These symptoms suggest that there may be inflammation in the skin – an increased activity from the immune system.

To study what was happening in the areas of hair thinning, the researchers compared immune activity in skin at the top of the head, to skin from the back of the head. They found that there was indeed an increased activity of immune cells in areas affected by hair loss, specifically around the upper regions of the hair follicles. This upper part of the hair follicles is where stem cells are stored, which are important for regenerating the hair follicle through its phases of growth and rest. If the immune cells are attacking this area, it could stop the stem cells from doing their work to regenerate the hair follicle. This may explain why hair follicles are not able to grow to their full size, and shrink over time, in people with pattern hair loss.

This was a small study, that did not look at immune cells directly, but rather the expression of genes and inflammatory markers, as a measure of how active the immune cells are. More research will be needed to understand if it might be possible to treat FPHL with treatments that try to calm down the immune system. 

Still, these findings give support to the idea that hormones are not the driving factor behind FPHL in most women. Doctors find that most women with FPHL have normal hormone levels, so androgen hormones which were long believed to be the cause, do not appear to be driving pattern hair loss. This is also the reason why experts now prefer using the term FPHL for this condition, rather than androgenetic alopecia (AGA).

The FPHL study from the researchers in China was published in the Journal of Investigative Dermatology in December 2025. A commentary from dermatologist Professor Yuval Ramot exploring the clinical implications was published alongside it.

We will continue to follow this line of research and let our community know about further developments.