Nulexin is the first product specifically developed to help reduce the appearance of serious dark circles. Nulexin is not a concealer. It's a revolutionary way to reduce the appearance of serious dark circles and discoloration in the per-orbital (eye) area. Nulexin reduces the appearance of serious dark circles by helping to reduce hemoglobin degradation byproducts through optimization of enzymatic activity in the peri-orbital tissue.