Metals in Female Scalp Hair Globally and Its Impact on Perceived Hair Health

A global study involving over 300 individuals from nine countries analyzed the levels of endogenous and exogenous metals in female scalp hair. The study found that metal levels, including calcium, magnesium, copper, and iron, varied widely and increased from root to tip, indicating environmental contact. Redox active metals like copper and iron, which can affect hair health through UV exposure or hair coloring, were present at similar levels in both colored and non-colored hair. However, water hardness ions were higher in individuals who colored their hair. Those who perceived their hair health as poor had higher metal levels. The study suggested that controlling metal binding and their damaging effects could improve perceived hair health.