Lip balm or lip salve is a wax-like substance applied topically to the lips of the mouth to moisturize and relieve chapped or dry lips, angular cheilitis, stomatitis, or cold sores. Lip balm often contains beeswax or carnauba wax, camphor, cetyl alcohol, paraffin, petrolatum, and lanolin, among other ingredients. Some varieties contain dyes, flavor, fragrance, phenol, salicylic acid, and sunscreens. Emollients or moisturizers (/ ɨˈmɒliənts/) are complex mixtures of chemical agents specially designed to make the external layers of the skin (epidermis) softer and more pliable. They increase the skin's hydration (water content) by reducing evaporation. Naturally occurring skin lipids and sterols, as well as artificial or natural oils, humectants, emollients, lubricants, etc., may be part of the composition of commercial skin moisturizers. They usually are available as commercial products for cosmetic and therapeutic uses,
The primary purpose of lip balm is to provide an occlusive layer on the lip surface to seal moisture in lips and protect them from external exposure. Dry air, cold temperatures, and wind all have a drying effect on skin by drawing moisture away from the body. Lips are particularly vulnerable because the skin is so thin, and thus they are often the first to present signs of dryness. Occlusive materials like waxes and petroleum jelly prevent moisture loss and maintain lip comfort while flavorants, colorants, sunscreens, and various medicaments can provide additional, specific benefits. Moisturizers but can also be made at home using common pharmacy ingredients. Moisturizers can be used to prevent the skin from becoming too dry or oily, such as with light, non-greasy water-based moisturizers. Such moisturizers often contain lightweight oils, such as cetyl alcohol, or silicone-derived ingredients, such as cyclomethicone.