The invention relates to a novel agent containing fat (oil), which contains onion extract, in addition to the production and use thereof for caring, preventing or treating damaged akin tissue, such as after operations, biopsies, wounds, burns and other accidents, and especially scarred tissue, stretch marks, degenerative skin conditions and others. The agent is characterised in that the base thereof is based on oil, which can be used to produce, for example, cream, lotion, fluid, massage, or balm based products which contain fail (oil). Surprisingly, the onion extract, which contains water, alcohol or water-alcohol, can be integrated into a base containing oil without the effectiveness thereof being reduced or a phase separation being produced. The effectiveness thereof could be proved when the medical application thereof was monitored.