Obagi Nu‑Cil Eyebrow Boosting Serum features NouriPlex Technology—a clinically proven blend of biotin, panthenol, sodium hyaluronate, and a proprietary lipid compound designed to support the appearance of fuller, thicker, darker eyebrows. In a 12-week study, 100% of participants saw improved brow fill after just 8 weeks, and 96% reported