The Naked Scientists Podcast What can we do about hair loss?
Aug 26, 2025
This week’s guests are Justine Hextall, a consultant dermatologist, and Asim Shamalak, a Harley Street hair transplant surgeon. They delve into the causes of hair loss and the influence of hormones and aging. Justine discusses the psychological effects while Asim breaks down the hair transplantation process and its success rates. They also explore societal stigma around baldness, modern wig technology, and the evolving perceptions of hair transplants, shedding light on why confidence matters in addressing hair loss.
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How Hair Is Made And Grows
- Hair is a tough keratin-rich fibre produced by follicles that remain embedded in skin.
- Follicles are permanent engines that push out dead, keratinised hair at ~0.2–0.3 mm/day.
Hair's Cellular Architecture
- Different keratinocyte types build medulla, cortex and cuticle so hair has layered structure.
- Melanocytes add pigment, so colour and structure depend on coordinated cell interactions in the follicle.
Why Hair Colour Varies By Ancestry
- Hair and skin pigmentation reflect evolutionary selection for UV protection, so darker pigments prevailed in high-sun regions.
- As humans migrated north, relaxed UV pressure allowed diverse hair and eye colours to evolve.