Traditional sunscreens are currently attracting significant attention because of the concerns that have been raised on their potential negative impact on human health and environment due to the occurrence of negative photochemical reactions after UV absorption. Natural UV-absorbing molecules are therefore gaining significant attention as new-generation sunscreen candidates, owing to their skin-friendly nature, biocompatibility, and environmental sustainability. However, for their further application it is key to understand at a fundamental level the photon energy dissipation pathways at work in these molecules. In this thesis, we primarily employ high-resolution laser spectroscopy based on resonance-enhanced multiphoton ionization techniques, combined with time-dependent density functional theory (TD-DFT) methods, to investigate the dynamics of the excited states and electronic structure of several natural sunscreen molecules after UV light absorption, including methyl sinapate, flavone, resveratrol, and urocanic acid with its derivatives. Based on the spectroscopic and dynamic properties of these molecules, we present a thorough overview of their modes of action during and after UV absorption. Further exploration of the influence of a solvent environment and of substitutions enable us to assess their potential as a new generation of UV absorbers. Undoubtedly, these results will pave the way for the development of safer and more sustainable sunscreen formulations without adverse effects on human health and the environment.