An enzyme known as angiotensin converting enzyme (ACE) produces a contraction in blood vessels by converting angiotensin I to angiotensin II in the body. [Angiotensin is a blood-vessel constrictor]. This resulting contraction in blood vessels leads to an increase in blood pressure to be able to force the blood through a narrower pipe. Now, C12 peptide is a natural enzymatically hydrolyzed casein protein derivative (some peptides are biologically active whey-protein hydrolysates). C12 peptide works by inhibiting the action of the angiotensin converting enzyme. By effectively inhibiting this enzyme, C12 may help to reverse blood-vessel constriction, and restore the elasticity of blood vessels, leading to reduced or normalized blood pressure.