Levomefolic acid (5-MTHF) is the natural, active form of folic acid used at the cellular level for DNA reproduction, the cysteine cycle and the regulation of homocysteine among other functions. IC50 value: Target: Folate analog Levomefolic acid has been proposed for treatment of cardiovascular disease and advanced cancers such as breast and colorectal cancers. Levomefolic acid (5-MTHF) has the prominent antioxidant activity. A high dose of 5-MTHF or folic acid does not influence Natural killer (NK) cell function in vitro.