The concept of clean beauty lacks a precise definition and its defining attributes remain unclear. This study assesses the impact of clean beauty on Millennial and Generation Z consumers, identifies its main attributes, and provides a new index for determining products’ cleanness. To this end, 120 Korean participants were recruited; they used 10 cosmetic products and completed relevant questionnaires. Clean beauty awareness and product satisfaction were assessed from the cognitive and emotional perspectives. The Reliable Cleanness Score (RCS) was calculated using emotional product satisfaction. Participants’ preference for clean beauty products was correlated with engaged cosmetic shopping behaviors. The key clean beauty attributes were sustainability, safety, and ethicality—in that order. Machine learning-based regression analysis showed that objective and subjective data could be used to calculate the RCS, resulting in an R² value of .721. With the results of this study, manufacturers, retailers, and consumers will be able to predict RCS.

Hair loss is often associated with oxidative stress and mitochondrial dysfunction in human follicle dermal papilla cells (HFDPCs), resulting in impaired cellular function and follicle degeneration. Thus, many studies have been conducted on natural plants aimed at inhibiting hair loss. This study investigated the therapeutic potential of exosomes derived from the rhizomes of Iris germanica L. (Iris-exosomes) in HFDPCs damaged by dihydrotestosterone (DHT). Iris-exosomes significantly reduced reactive oxygen species (ROS) levels, restoring mitochondrial membrane potential and ATP production, thereby mitigating oxidative stress and improving mitochondrial function. These effects occurred alongside enhanced cellular processes critical for hair follicle regeneration, including increased cell migration, alkaline phosphatase (ALP) activity, and three-dimensional (3D) spheroid formation, which replicates the follicle-like microenvironment and promotes inductive potential. Furthermore, Iris-exosomes stimulated the Wnt/β-catenin signaling pathway by enhancing glycogen synthase kinase-3β (GSK-3β), AKT, and extracellular signal-regulated kinase (ERK), leading to β-catenin stabilization and nuclear translocation, thereby supporting the expression of genes essential for hair growth. Taken together, these findings suggest that Iris-exosomes can be promising ingredients for alleviating hair loss.

Reactive oxygen species (ROS) bursts from photoaging cause skin damage and chronic conditions. Understanding spatiotemporal ROS dynamics is critical for developing therapies and cosmetic strategies to enhance skin health. Conventional assays and fluorescence microscopy lack the resolution for real-time ROS quantification due to photobleaching and labeling issues. Here, we developed a label-free, real-time monitoring platform with high spatiotemporal resolution using a near-infrared (nIR) fluorescent single-walled carbon nanotube (SWNT) nanosensor array to quantify ROS bursts from daily photoaging. The SWNT array, dual-functionalized with DNA and poly- l -lysine, achieved selective H ₂ O ₂ recognition and skin cell compatibility. The skin cell–friendly nanosensor interface (SNI) enabled attomole-level detection of H ₂ O ₂ bursts in a two-dimensional keratinocyte model under natural ultraviolet exposure, revealing photoadaptation behavior. Distinct oxidative stress wave profiles were identified via nIR data and numerical modeling. Using SNI, we introduced the anti-ROS score to evaluate skin care antioxidants, providing insights into photoaging pathways and cosmetic advancements.

Objective: Alfalfa ( Medicago sativa ) is a prominent herbal treatment among Asian countries and its antioxidant and anti‐inflammatory effects have already been generally elucidated. Excessive melanin synthesis is one of the major troubles in the cosmetics industry, thus such research has been extensively described. Here, we investigated the anti‐melanogenic effects and molecular mechanisms of two types of alfalfa extracts: alfalfa ethanol precipitate (AEP) and alfalfa ethanol supernatant (AES). Methods: The chemical composition of AEP and AES was analysed using HPAEC‐PAD and LC–MS/MS. B16F10 cells and MNT‐1 cells were used to demonstrate the inhibitory effect of two alfalfa seed extracts on melanin synthesis. The gene expression and protein levels of tyrosinase, tyrosinase‐related protein 1 (TRP1), DCT and microphthalmia‐associated factor (MITF) were confirmed using semi‐quantitative RT‐PCR, western blot and immunocytochemistry. Furthermore, the underlying mechanisms of these factors were elucidated in B16F10. The inhibitory effect on melanogenesis was validated using 3D artificial skin (MelanoDerm). Results: Both AEP and AES reduced melanin content in B16F10 cells stimulated with α‐melanocyte‐stimulating hormone (α‐MSH) and subsequently decreased mRNA and protein levels of the melanogenesis‐related targets, tyrosinase, TRP1 and MITF, as shown by semi‐quantitative RT‐PCR and immunocytochemistry. In addition, AEP and AES reduced protein levels of the MITF upstream regulators such as extracellular signal‐mitogen‐activated protein kinases (ERK), cAMP response element‐binding protein (CREB) and β‐catenin. Similar inhibition of melanin production and decreased expression of tyrosinase protein and MITF mRNA and protein were also confirmed in MNT‐1 human melanoma cells. Using artificial human skin tissue (MelanoDerm), a significant reduction in melanin content was observed. Conclusion: Alfalfa seed extracts exert an inhibitory effect on the melanin production process by modulating the activity of ERK, CREB and β‐catenin, thereby suppressing MITF and reducing the levels of tyrosinase, TRP1 and DCT. Collectively, these findings suggest that alfalfa extracts may be a promising avenue for further research and development in the fields of cosmetics and pharmaceuticals.