Unlocking Nature’s Anti-Aging Secrets: The Potential of Natural Mineral Waters Combined with Plant Extracts in Cosmetics

Skin aging is influenced by intrinsic and extrinsic factors, leading to structural changes in the skin. Current anti-aging cosmetic trends emphasize innovative natural ingredients, including plant extracts, thermal waters, and botanical hydrolats. This work aims to develop six natural anti-aging cosmetics (two serums, two day creams, and two night creams) with innovative and non-irritating profiles. The rational design was guided by market analysis and ingredient properties. Prototype formulations were created with two core mixtures: (1) natural mineral water from Termas de Unhais da Serra and Thymus × citriodorus hydrolat and (2) natural mineral water from Termas de Chaves and aqueous Vaccinium myrtillus (blueberry) extract. The products were evaluated for stability (4 °C and 40 °C, 4 weeks), safety (according to EC Regulation No. 1223/2009), including in vitro testing for skin irritation potential (epiderm model; OECD TG 439). The market study highlighted a gap in anti-aging products combining natural extracts and thermal waters. All prototypes showed desirable textures and remained stable under test conditions. No irritating effects were observed. The results support the development of effective anti-aging cosmetics rooted in natural resources. These innovative products can meet the market demand for natural and sustainable skincare solutions.