Serums are concentrated treatments formulated to have an immediate and strong effect on the skin's health, tone, or definition. They are thinner than creams.
A serum is a cosmetic skincare product used to moisturize, heal, plump up, and/or smooth the skin. Usually oil- or water-based, serums are much less viscous than creams, and can be up to ten times as concentrated with active ingredients.
How it works: Serums are effective because their formulas include such high concentrations of their active ingredients. Antioxidants are reducing agents, which allow themselves to be oxidized by free radicals so that your own cells aren't damaged by them. Peptides, polypeptides, and hyaluronic acid all plump and smooth the skin by promoting collagen and elastin (skin protein) production. Aloe vera, which contains a number of active compounds, is known as an effective soother and healing agent.
Buy: Serums are available at pharmacies, cosmetics stores, and online. Prices vary drastically based on ingredients and brand, from $20 to $300. Vials of serum are usually sized to last three to six months.