A cosmetic is any substance, which is applied to the body for cleansing, beautifying, promoting attractiveness or altering the appearance. The range of products used by public now a day as cosmetics is wide. In case of skin, they are moisturizers, cleansers, soap, foundations, facials, powders, eye cosmetics and lip cosmetics. For nails, they are nail polishes/enamels, enamel removers, hardeners, cuticle removers and artificial nails. Various cosmetics used for hair are shampoo, conditioner, bleach, hair dyes and oils, permanent waving, straightening agents, and depilatories (hair removing agents).
It is not at all clear that normal skin benefits from much, if any thing at all, in the way of specific care, except for protection from harsh chemical and physical agents especially sunlight. On the other hand, many products used for
skin care or cosmetic purposes can occasionally produce adverse reactions, such as allergic and irritant
contact dermatitis, phototoxic and photoallergic reactions, and induction of acne (
acne cosmetica). Neither price range nor brand name (standard products versus substandard) provides absolute assurance that a given product will be highly effective or will not cause adverse reactions.
Use of cleansing creams instead of soap has no benefits and may induce acneiform lesions. Facial
massage, saunas, pore cleaning, facials etc may temporarily improve the appearance of skin, but have not been shown to have any long term beneficial effects, other than looking and feeling good. The normal
epidermis, hair follicles and nail matrices receive their nutrition from the dermal vasculature and there is no evidence that any topically applied nutrient can enhance their performance.