Are hair cortisol levels dependent on hair growth rate? A pilot study in rhesus macaques

•Hair growth rate does not correlate with hair cortisol concentrations in macaques.•Adult macaques had faster hair growth but lower hair cortisol than infants.•Higher hair cortisol is not due to cortisol-mediated inhibition of hair growth.•Macaques and humans are similar in hair growth rates and HPA axis regulation.