What this means
Melanogenesis and pigmentation are crucial processes for normal skin and hair, and they are regulated by complex factors. Unlike epidermal pigmentation, follicular melanogenesis depends on cyclic replenishment from a bulge melanocyte stem cell reservoir, making its functional decline generally irreversible yet clinically reversible under rare conditions.
A plain-English summary is on its way. Until then, this is the start of the authors' own summary.
- Who it was tested in
- Earlier studies
- Kind of research
- A summary of earlier studies
The science
- Original title
- Unraveling hair graying: insights into melanocyte biology and the aging process.
- Authors
- Chen SY, Weng HJ, Yeh YW et al.
- Journal
- Frontiers in cell and developmental biology
- Published
- Oct 24, 2026
- Study type
- Review
- PMID
- 42920478 ↗
Abstract
Melanogenesis and pigmentation are crucial processes for normal skin and hair, and they are regulated by complex factors. Unlike epidermal pigmentation, follicular melanogenesis depends on cyclic replenishment from a bulge melanocyte stem cell reservoir, making its functional decline generally irreversible yet clinically reversible under rare conditions. Herein, we systematically review the core biological processes governing follicular pigmentation, including embryonic specification, niche homing, cyclic lineage migration, and microenvironmental signaling networks. We further integrate emerging single-cell and spatial omics findings to propose a novel, three-stage chronological model of canities, bridging mouse-derived mechanisms with human clinical evidence. There are multiple conditions that lead to hair graying, such as aging, premature hair graying, the stem cell niche environment, and the biological variety of melanocytes and hair follicles, with aging being the most common factor among these. In brief, the exact mechanisms of hair pigmentation and depigmentation remain elusive. Herein, we review the physiology and pathology of hair pigmentation and depigmentation, and summarize the mechanisms that might be affected during human hair graying.
Chen SY, Weng HJ, Yeh YW et al. Unraveling hair graying: insights into melanocyte biology and the aging process. Frontiers in cell and developmental biology. 2026. doi:10.3389/fcell.2026.1815236. PMID: 42920478. https://pubmed.ncbi.nlm.nih.gov/42920478/