15 citations
,
October 2020 in “European journal of pharmaceutics and biopharmaceutics” Caffeine penetrates skin quickly through open hair follicles, but less through closed ones, with levels becoming equal after 22 hours.
Copper levels in green hair decreased significantly after treatment.
10 citations
,
January 1985 in “PubMed” Trace elements like calcium, iron, and zinc are unevenly distributed in hair, while sulfur is even, and increased phosphorus and potassium levels are linked to skin reactions.
10 citations
,
January 1980 in “Ultrastructural pathology” Green hair has high copper levels due to contaminated water and damaged hair cuticles.
4 citations
,
February 2007 in “Journal of the European Academy of Dermatology and Venereology” The study suggests silicon might be important for healthy hair, as less silicon was found in people with hair loss.