The obvious answer is that a product expires when it no longer works. But when it comes to moisturizers, how does one really know? And how old does a shampoo bottle have to be before it stops cleaning the hair? Products lose their effectiveness slowly over time and of course, this depends on the conditions under which the products are stored. Products stored on a window sill exposed to the heat of the sun become less effective sooner than the same product stored in a cool dark cabinet.
Shampoo is quite a recent invention with the first synthetic shampoo, Drene, being introduced in the United States in the 1930s. Shampoo didn't become a household staple until the early 1960s when products like Breck, Prell, and Johnson & Johnson's Baby shampoo became popular. Prior to that, hair was typically washed with bar soap.
A "Night Cream" is a moisturizer. Yes, it is often (but not always) thicker, found in a smaller jar, and more expensive per ounce than a conventional facial moisturizer. Night creams sold on skincare aisles are formulated just like other facial moisturizers.
Petroleum jelly, also known as petrolatum, is an odorless, tasteless semisolid mixture of hydrocarbons recognized by the U.S. Food & Drug Administration (FDA) as an approved over-the-counter skin protectant. It is widely used in the cosmetic skincare industry found in more that half of all skincare products sold today. Not to be confused with industrial grade petrolatum, which may contain pore-clogging impurities, well-manufactured cosmetic grade petroleum jelly is non-comedogenic (does not block pores) and is not a skin irritant.
What exactly is a serum? The term serum is a medical term referring to the clear liquid in blood after both the cells and clotting factors are removed. Somehow this term morphed into a kind of cosmetic that most consumers assume is a clear water-based liquid with the promise to brighten skin, decrease wrinkles, improve pigmentation, improve tone and texture, give the skin a younger appearance, and more. Fact is there is no standard definition for the formulation of a serum, neither from the U.S Food and Drug Administration (FDA), from cosmetic chemists or dermatologists.
Koala bears aren't really bears. Jellyfish aren't really fish. And moisturizers don't really add water to the skin. And it's a good thing the skin doesn't absorb water or we'd swell up like a sponge when we swam in the ocean. And we don't.
Deodorants are cosmetics formulated to mask body odor, to make the skin smell better. They commonly contain odor-masking fragrance. They can be formulated as aerosols and sprays, pumps, roll-ons, solid sticks, gels and creams. Deodorants do not prevent sweating. Antiperspirants are over-the-counter drugs, regulated by the US Food and Drug Administration (FDA).
FALSE: You don't NEED a toner.
Toner, the skincare product that is as varied in formulation as is the list of their alleged benefits. The benefits touted by health and beauty magazines for toners are endless. They supposedly cleanse, shrink pores (note: like the length of your arms, pore size does not change), remove dirt, pollen, and pollution, hydrate, soothe and calm, repair, balance the skin's pH, nourish, stimulate blood circulation, function as an antibacterial, clear blemishes, and more.
Reduce Under Eye Bags and Puffiness!
Fade away those Dark Circles & Rings!
Wipe away Fine Lines & Wrinkles from around your eyes!
Examples of typical marketing jargon found on "eye" creams sold at department stores, local pharmacies, and on-line.