26 citations
,
December 2009 in “Laser Physics” This study observed that caffeine-containing shampoo can penetrate hair follicles to a depth of approximately 200 μm and remains detectable even after 24 hours, suggesting a potential long-term reservoir effect.
24 citations
,
February 2007 in “Laser Physics Letters” This study found that a caffeine-containing shampoo penetrated deeply into hair follicles in just two minutes and remained there for up to 48 hours, even after washing.
26 citations
,
April 2011 in “Skin Research and Technology” This study found that in vivo confocal scanning laser microscopy accurately quantifies neogenic hair follicles in mice, producing results similar to histology while avoiding fixation artifacts.
January 2022 in “OPAL (Open@LaTrobe) (La Trobe University)” This study used advanced optical imaging techniques to investigate nanoparticle and dye penetration in human skin, finding that nanoparticles mainly resided in the stratum corneum and accumulated in skin folds and hair follicles, while highlighting that sunscreen-based nanoparticles appear unlikely to pose safety concerns.
46 citations
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May 2006 in “Laser Physics” In this study, particles similar in size to keratin cells were surprisingly found to penetrate more efficiently into hair follicles due to a possible pumping effect from moving hairs.
