###### Abstract
The increasing use of AuNPs has led to a higher environmental burden from their production and product waste. Nanomaterials evolve chemically and physically over time through a complex combination of processes such as aggregation, biological assimilation, dissolution and evaporation, chemical alteration, shape change, and movement within the Earth's system [8]. The complete impacts of nanomaterials on the environment are largely unknown, but local, regional and global systems are certainly affected by their presence. The potential reuse of nanomaterials and life cycle assessments are gaining attention to reduce these environmental impacts [6]. While AuNPs bring functional benefits to cosmetic products, their production and integration into cosmetic formulations carry significant environmental burdens. The cosme industry is resource-intensive, relying on energy, water and raw materials, contributing to various environmental impacts, including greenhouse gas emissions, resource depletion and ecotoxicity [9]. As such, evaluating the environmental performance of cosmetic creams containing AuNPs through LCA is critical to identifying hotspots and developing strategies to mitigate environmental harm. Hyper-Harmonized Hydroxylated Fullerene Water Complex (3 HFWC) is an additional nanomaterial in the investigated cosmetic cream, which has beneficial cosmetic effects, promoting hydration and anti-ageing effects [10]. On cosmetic products, it may also be designated simply as \"hydroxylated fullerene\". Fullerene is composed of around 60-80 carbon atoms in pentagon and hexagon configurations in the shape of a sphere. The addition of hydroxyl groups (OH group) to the surface of the fullerene sphere creates a hydroxylated fullerene [C60(OH)x], or fullerene, which is soluble in water and polar solvents, unlike fullerene. A Hyper-Harmonized Hydroxylated Fullerene Water Complex, or 3 HFWC is formed by functionalizing fullerenols additionally by means of water molecules and energy that oscillates according to icosahedral symmetry. This is another nanomaterial with sizes of 6-18 nm, for which the environmental impact and toxicity risks present a considerable challenge to determine. This study aims to perform a cradle-to-gate LCA of a cosmetic cream formulated with AuNPs and 3 HFWC, assessing the environmental impacts across the production process. The assessment covers the extraction of raw materials, nanomaterial ingredient synthesis, cosmetic cream manufacturing, and packaging, focusing on energy consumption, emissions and resource use. By examining these processes, the study seeks to provide a comprehensive evaluation of the product's environmental footprint, and identify opportunities for reducing its environmental impact. Furthermore, this LCA will enable a comparison of the environmental performance of cosmetic creams containing novel ingredients like AuNPs with other products on the market, contributing to broader efforts towards sustainability in the cosmetics industry. In light of the increasing regulatory pressures and consumer awareness of environmental issues, this study contributes to the growing body of research to improve sustainability in product development. The findings will provide valuable insights for decision-makers in the cosmetics industry, including product designers, manufacturers and sustainability strategists, facilitating the creation of products that meet consumer expectations and align with global environmental goals.