122 citations
,
October 2010 in “Clinica Chimica Acta” Washing hair with water or shampoo lowers cortisol levels in hair.
22 citations
,
January 2010 in “Clinical Medicine Insights Endocrinology and Diabetes” Forearm hair has more cortisol than lower leg hair.
90 citations
,
July 2014 in “Conservation Physiology” Hair cortisol levels in brown bears can be affected by both long-term and short-term stress.
50 citations
,
November 2020 in “Physiology & behavior” People with depression often have higher hair cortisol levels, while those with PTSD tend to have lower levels, but more research is needed to understand this fully.
33 citations
,
January 2017 in “Psychoneuroendocrinology” Hair dyeing and washing frequency do not affect hair cortisol levels.