A: Superoxide dismutase. This is an enzyme produced by the body to neutralize the superoxide radical. Superoxide is a messenger of inflammation and is involved in the body's autoimmune response. It exists in a yin-yang relationship with nitric oxide. Nitric oxide is a vasodilator that appears to be important for hair growth, while superoxide is a vasoconstrictor that may be part of the signaling mechanism that tells hair to stop growing. Superoxide can also interact with nitric oxide to form a highly destructive free radical called peroxynitrite, which causes protein and lipid oxidation. A few hair loss products contain copper peptides, which are SOD mimetics; i.e., mimic the effects of the body's SOD enzyme. SOD-containing products have been noted a number of times by researchers to stimulate hair growth and block hair loss in mice. Recent study data on Tricomin, a copper peptide SOD, indicates increased hair growth in male pattern baldness. Among other beneficial things, SODs appear to help spare growth-stimulating nitric oxide, reduce damaging inflammation, and help reverse fibrosis (follicular scarring). There are a few patents for SODs as hair growth stimulators and even one for an SOD inhibitor that blocks hair growth by increasing superoxide.
