January 2023 in “Research Square (Research Square)” This study found that glycated proteins in untreated scalp hair may serve as a non-invasive marker for blood glucose control, but its applicability is limited by factors like cosmetic treatments and sample collection challenges.
4 citations
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May 2021 in “Molecules” This study suggests that analyzing hair samples with a liquid chromatography-mass spectrometric assay may offer a reliable method to measure average quarterly vitamin D levels, potentially complementing blood tests.
33 citations
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January 2017 in “Conservation physiology” This study found that measuring reproductive hormone levels in brown bear hair may effectively support non-invasive genetic sampling, though larger samples or more sensitive techniques are needed for broader application.
March 2025 in “bioRxiv (Cold Spring Harbor Laboratory)” This study found that HairTime, a novel non-invasive assay using hair samples, accurately estimates chronotype and reveals its plasticity influenced by work schedules and lifestyle factors.
199 citations
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July 2007 in “General and Comparative Endocrinology” In this study, researchers found a significant positive association between cortisol levels in hair and feces of domestic cats and dogs, suggesting hair cortisol assays could be a viable option for monitoring chronic stress.