What is a common purpose of serums in hair care?

Serums in hair care are often designed to enhance the hair's appearance and texture, with a common goal of providing shine and smoothness. These products typically contain concentrated ingredients that coat the hair strands, helping to tame frizz and create a glossy finish. This makes hair look healthier and more polished, which is particularly desirable for various styles and looks.

While hydration of the scalp, encouragement of hair growth, and protection from UV damage are important considerations in overall hair care, serums specifically focus on the external presentation of the hair itself. They are formulated to improve the hair's surface, smoothing out roughness and enhancing its natural luster, rather than addressing deeper concerns like scalp health or growth stimulation. Thus, the primary function of serums aligns best with providing shine and smoothness, making this the correct choice.