The Lactuca genus, which is characterized by a variety of forms including annual, biennial and perennial, glabrous or pubescent herbs with abundant latex, belongs to the Asteraceae family. Lactuca is an essential source of phytochemicals and is used in traditional medicine. The authors discuss Lactuca sativa's anti-inflammatory, antioxidant, antidiabetic, antimicrobial, analgesic, sedative and neuroprotective effects. The antibacterial effects of Lactuca sativa extracts are evaluated using the microwell dilution method against a wide range of clinical isolated bacteria, and the antioxidant effects are tested using ferric-reducing antioxidant power and catalase activity assay. The genetic transformation of lettuce is examined in conjunction with the applications of this transformation in plant biotechnology. The potential for Ulva lactuca to be used as a bioindicator of contamination is studied, as well as its capability to be employed for the removal of pollutants. The authors explore the hypothesis that if a sufficient amount of free vitamin B12 can be incorporated into lettuce leaves grown under hydroponic conditions, lettuce could become an excellent source of vitamin B12 for vegetarians and elderly people.