Copper is an essential trace mineral involved in numerous physiological processes, including the maintenance of healthy hair. Scientifically, copper acts as a cofactor for several enzymes (cuproenzymes) that are critical for melanin production (the pigment responsible for hair color), such as tyrosinase. Adequate copper is necessary for the cross-linking of collagen and elastin, which contribute to the structural integrity of skin and hair follicles. Copper deficiency has been associated with depigmentation of hair (premature graying) and, in rare cases, hair thinning or loss, as shown in clinical and animal studies (Prohaska, 1990).

However, copper deficiency is uncommon in healthy individuals, and supplementation beyond dietary needs has not been conclusively shown to enhance hair growth or prevent hair loss in the general population. Most evidence supporting copper's role comes from deficiency or genetic disorder models (e.g., Menkes disease), rather than from studies on supplementation in people with normal copper status. In summary, while copper is scientifically validated as essential for normal hair pigmentation and structure, there is only moderate evidence for its use as a supplement specifically to support hair health unless a deficiency exists.