21 citations
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December 2019 in “PloS one” The rat model showed early perimenopause with regular cycles and low hormones, and late perimenopause with irregular cycles and higher hormone levels.
14 citations
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June 2001 in “Endocrinology” Prolactin affects when mice shed and grow hair.
1 citations
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March 1989 in “Proceedings of the British Society of Animal Production” Hormones and daylight changes control when cashmere goats shed their hair.
49 citations
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May 2018 in “Endocrine” Women with regular menstrual cycles and PCOS have linked kisspeptin and LH hormone patterns, unlike those with irregular cycles.
August 2017 in “Journal of animal science/Journal of animal science ... and ASAS reference compendium” Melatonin supplementation may lower skin temperature in unshaved areas of pregnant beef cattle.
22 citations
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June 2017 in “Stem cell reports” PTEN helps control the number and health of skin stem cells by working with the protein BMAL1.
40 citations
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November 2011 in “American Journal of Human Biology” Stress from being transgender is linked to higher blood pressure at night and more inflammation, which may affect heart health.
January 2002 in “HAL (Le Centre pour la Communication Scientifique Directe)” Melatonin affects fur growth timing in chinchillas.
15 citations
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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.
August 1994 in “Molecular Endocrinology” Changing protein kinase levels in pituitary cells affects calcium flow and beta-endorphin release.
16 citations
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November 2005 in “Journal of Clinical Pathology” CD1d expression in scalp skin and hair follicles changes with the hair cycle and may help protect against microbes.
April 2026 in “Journal of Experimental Psychopathology” Hair cortisol levels may not reliably indicate psychological distress.
2 citations
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April 2018 in “SLEEP” People with rheumatoid arthritis have poorer sleep quality than healthy individuals.
6 citations
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October 2018 in “PLoS ONE” Stress can slow hair growth and affect skin color by impacting the body's stress response system.
September 2017 in “Journal of Investigative Dermatology” Hair follicle cells change their DNA packaging during growth cycles and when grown in the lab.
September 1997 in “Journal of the European Academy of Dermatology and Venereology” Hirsute women with ovarian-sourced hirsutism are more likely to have irregular periods, with higher BMI and altered hormone ratios.
April 2024 in “Journal of wildlife diseases” Muskox hair growth rates vary widely, so a single growth rate can't be used for all populations.
50 citations
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July 2018 in “Psychoneuroendocrinology” Hair cortisol can indicate long-term stress levels, but hair growth rate differences may affect accuracy.
17 citations
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August 2018 in “BMC Genomics” The HOXC13 gene affects different hair proteins in cashmere goats in varied ways and is controlled by a feedback loop and other factors.
44 citations
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February 2023 in “Cell” Fingerprints form uniquely before birth due to specific genetic pathways and local signals.
14 citations
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December 2013 in “Experimental Dermatology” The T-zone on the face has more androgen receptors and produces more oil than the U-zone.
14 citations
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January 1977 in “PubMed” The hair keratin variant is mostly found in Caucasians.
February 2019 in “Psychoneuroendocrinology” Hair samples can reliably show average long-term hormone levels in young women.
January 2018 in “Springer eBooks” Gender affects hair and scalp characteristics, with differences in hormone responses, graying patterns, and trace metals.
16 citations
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January 2021 in “Frontiers in veterinary science” Pigs in farrowing crates and loose-housing systems showed no difference in chronic stress levels as measured by hair cortisol.
January 2026 in “Applied Sciences” Cyclic ADP-ribose helps regulate calcium and signals that promote hair growth in hair follicle cells.
June 2008 in “CRC Press eBooks” PCOS may have evolved as an advantage in past environments with food scarcity.
11 citations
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April 1993 in “PubMed” Human hair cells can change based on their environment, especially interactions with certain skin cells.
April 2026 in “npj Parkinson s Disease” VPS13C variants are linked to more severe REM sleep disorder and faster progression to Parkinson's disease.