Our hair is a marker of beauty, pride, and health integral to our identity and how others perceive us. Conversely, hair loss can cause a great deal of emotional strain and reduce our quality of life.

Hair restoration treatments are limited to either surgical (hair transplantation) or non-surgical (drugs) methods. So, finding a novel – preferably non-invasive – hair loss treatment is understandably high on some researchers' lists. Researchers from the Yokohama National University (YNU) in Japan hope that cinnamon is that sought-after novel treatment.

They'd previously found that the so-called 'love hormone' oxytocin promoted hair growth by upregulating genes in the dermal papilla cells that are pivotal in hair formation, growth, and cycling. However, an issue with administering oxytocin through the skin so that it activates this hair-growth pathway is that it's a relatively large molecule, so absorption is prevented.

Enter cinnamon or, more precisely, cinnamic acid from Chinese cinnamon (Cinnamomum cassia). Cinnamon is already known to possess wide-ranging health benefits, including skin-anti-aging effects and was recently discovered to enhance skin elasticity through its effect on oxytocin receptors. Cinnamic acid, which is widely used in cosmetics, is a fraction of the molecular weight of oxytocin.

The researchers evaluated the effects of cinnamic acid on the expression of oxytocin and hair growth-related genes. Dermal papilla cells were cultured with different acid cinnamic concentrations, ranging from 0 to 2,000 µg/mL. Concentrations of 1,000 and 2,000 µg/mL were observed to cause cell damage and, above 500 µg/mL, considerably inhibited cell proliferation. However, at concentrations below 500 µg/mL, there was an observable dose-dependent increase in the expression of oxytocin and genes associated with hair growth.