The European Food Safety Authority (EFSA) issued a scientific opinion at the request of the European Commission regarding the safety and efficacy of L-lysine monohydrochloride and liquid L-lysine. These substances are produced by fermentation using a genetically modified strain of the bacterium Corynebacterium glutamicum KCCM 80368 or KCCM 80479. The additives are intended as nutritional and sensory additives in feed and drinking water for all animal species and categories. L-lysine is an essential amino acid important for animal growth and development. The assessment focused on verifying the safety of these genetically modified strains and the efficacy of the produced products. The results serve as a basis for regulatory decisions in the European Union.