A revolutionary new study has fundamentally overturned the long-held scientific understanding of how human hair grows, a discovery that could rewrite biology textbooks and open the door to a new generation of hair loss treatments.
The 'Tiny Motor' Inside Your Follicle
For decades, it was a basic tenet of biology that hair emerged from the scalp due to an upward push generated by dividing cells at the root. However, research led by scientists at Queen Mary University of London, published in the journal Nature Communications on Monday 19 January 2026, has turned this theory on its head.
Using an advanced 3D time-lapse microscopy technique, the team was able to peer into living hair follicles in real time. They discovered that each hair is actively pulled upwards by a coordinated network of moving cells in the follicle's outer root sheath, acting like a microscopic motor.
"For decades, it was assumed that hair was pushed out by the dividing cells in the hair bulb," explained study author Inês Sequeira. "We found that instead it’s actively being pulled upwards by surrounding tissue."
Protein Disruption Halts Growth
The researchers tested their hypothesis by first blocking cell division inside the follicle. Contrary to expectations, hair growth continued almost unabated. The pivotal moment came when they disrupted the protein actin, which is essential for cellular movement and contraction.
This single intervention caused hair growth to plummet by more than 80 per cent, proving that mechanical pulling, not just cell proliferation, is the primary driver. Computer simulations later confirmed that the pulling force generated by actin-linked movement in the outer layers was key to the observed speed of hair extrusion.
"This approach reveals a spiral-like downward movement of outer root sheath cells entering the lower bulb region," the study noted. The team proposed a new model where this sheath generates a pulling force essential for hair fibre extrusion.
Implications for Future Hair Loss Therapies
The implications of this discovery are profound for the field of dermatology and regenerative medicine. By shifting the focus from cell division to the mechanical forces within the follicle, scientists now have a fresh target for intervention.
"This new view of follicle mechanics opens fresh opportunities for studying hair disorders, testing drugs, and advancing tissue engineering," said co-author Thomas Bornschlögl.
The live-imaging method itself is also a breakthrough, allowing researchers to test potential drugs and treatments in real time on living follicles. This could significantly accelerate the development of new therapies for alopecia and other hair growth conditions, moving beyond simply stimulating cell growth to precisely modulating the follicle's intrinsic 'pulling' mechanism.
