Nisinic acid is a very long chain polyunsaturated omega-3 fatty acid, similar to docosahexaenoic acid (DHA). The lipid name is 24:6 (n-3) and the chemical name is all-cis-6,9,12,15,18,21-tetracosahexaenoic acid. It is not well studied, but polyunsaturated fatty acids even longer than DHA, nisinic acid included, may hold scientific promise. It has biological activity and is involved in the formation of DHA, but the mechanisms are still under research.