In the dynamic landscape of the cosmetics market, claims based on consumer perception are increasingly prevalent due to the perceived authenticity they offer. However, quantifying perceived benefits that evolve over time, such as fine lines reduction or skin softness, presents a significant challenge. This paper introduces a robust, consumer-centric methodology specifically designed for substantiating claims related to such evolving benefits perceived by consumers. Our approach integrates a validated self-scoring scale inspired from the medical field and a rigorous study design. A pilot study conducted in France (n = 240) demonstrated excellent reproducibility and consumer understanding of the methodology. Furthermore, our findings highlight the methodology's sensitivity in capturing perceived benefit evolution, complementing traditional agreement scales. This research provides a framework for developing impactful, consumer-resonating claims while upholding rigorous scientific standards within the cosmetics industry.
Excessive scalp sebum makes hair appear greasy and reduces the height of the cranial, which affects physical appearance. It can also lead to scalp itching and even dandruff. However, previous studies have mainly focused on the cleansing ability of shampoos on scalp sebum, with fewer studies examining the sebum-controlling effects of shampoos containing active ingredients. In this study, a shampoo containing salicylic acid and zinc PCA (zinc pyrrolidone carboxylic acid) was tested on 30 individuals with oily scalps over 28 days. The results showed that immediate use significantly increased cranial crown hair height. After 28 days of use, it significantly reduced the sebum secretion of scalp and hair sebum quantities. It also significantly decreased the sebum secretion rate of the scalp and the rate at which hair becomes oily. Furthermore, volunteers significantly agreed that it improved scalp itching and redness issues. Overall, shampoo containing salicylic acid and zinc PCA not only provides immediate scalp sebum cleansing but also offers long-term sebum control without irritating the scalp.
Retinyl linoleate (RL) was compared to retinol in cultured keratinocytes and fibroblasts, human skin explants, and in a clinical study. RL induced gene expression characteristic of retinol, including HAS3 (hyaluronan synthetase 3, an enzyme that synthesizes hyaluronic acid from precursor sugars), and induced hyaluronic acid synthesis in both keratinocytes and fibroblasts equal to or better than retinol. RL also induced collagen production in fibroblasts comparable to retinol. In UV-irradiated human skin explants, those treated with RL showed less alteration of collagen and elastin than did similarly treated retinol samples. In a randomized, double-blind clinical study of photoaged women, RL was superior to retinol in improving skin appearance-particularly bounce, plumpness, brightening, and radiance-while reducing skin dryness and formula instability, compared to retinol. These data demonstrate that RL is superior to retinol for use in skin care formulations.
Synopsis The study aimed to comprehensively investigate the immunological mechanisms of essential oil allergy and to identify the key principles and factors that influence its effective therapy. The methodology included an analysis of scientific sources from 2019-2024 using the PubMed, Scopus, Web of Science, and ScienceDirect databases, which were used to select 53 relevant articles out of the initial 180 articles identified. The study established that the main sensitizing components of essential oils are oxidized forms of monoterpenoids (limonene and linalool) and phenolic compounds (eugenol and thymol), which interact with the skin, disrupt the integrity of cell membranes, and trigger an immune response. Furthermore, Langerhans cells present these allergens to T-lymphocytes, which leads to the activation of an adaptive immune response, and mast cells and basophils contribute to immediate reactions through the release of histamine and cytokines, which causes inflammation and allergic symptoms. Genetic predisposition and concomitant dermatological diseases, such as atopic dermatitis, increase the risk of developing allergies. Modern therapeutic approaches are based on antihistamines, corticosteroids, and immunotherapy, but their effectiveness is limited by the complexity of the chemical composition of essential oils and the individual variability of reactions. Promising treatments were proposed, including modification of the chemical composition of oils to reduce allergenicity, nanotechnology for controlled release of active substances and personalized immunotherapy using modified allergens and adjuvants. The results indicated the need to improve diagnostic and therapeutic strategies, including the development of individualized approaches to the treatment and prevention of essential oil allergies.
Protein-based hair care ingredients improve the texture of damaged hair. Supplemented proteins are thought to influence keratin proteins, the primary structural component of hair. However, the exact binding sites of hair care ingredients with keratin are unknown. In other words, understanding the binding mechanism between keratin and hair repair ingredients is the key to elucidating how hair repair occurs. Herein, we established the repair mechanism of S-carboxymethyl alanyl disulfide keratin (CMADK) at the molecular level using two complementary approaches. First, we synthesized keratin-derived peptides rich in alpha-helical structures. Second, we analyzed their interactions through circular dichroism measurements and high-performance liquid chromatography. Sequence alignment of peptides capable of forming alpha-helices revealed that the 375-404 region of Type II keratin K85 is a core region playing a central role in CMADK function. Overall, we present a model in which CMADK specifically binds to Type II keratin K85 (residues 375-404).
