I hope this glossary of skin care ingredients and terms will help you familiarize yourself with some of the terms used in our articles as well as terms used by your dermatologist.
Alpha hydroxy acids (AHAs) – Fruit acids found in plants that remove dead and damaged surface cells through exfoliation, making skin appear smoother and feel softer. They may help the appearance of fine lines. Other types of alpha hydroxy acids include glycolic acid, lactic acid, madelic and malic acid.
Antioxidants – Substances that slow or stop free-radical damage to cells. There are many different types of antioxidants as they are found abundantly in the nature. Many vitamins, such as vitamins A, C, and E have antioxidant properties. Coenzymes, such as alpha-lipoic acid and coenzyme Q10 also contain antioxidants, as do many plant-derived compounds. Names of other antioxidants used as skin care ingredients include ferulic acid, phloretin and citric acid.
Beta hydroxy acids (BHAs) – The main beta hydroxy acid used in skin care ingredients is salicylic acid. It is used particularly for acne, to prevent the formation of comedones (plugs) in the pores.
Ceramides – Ceramides are a type of fat (lipid) that is found in many cell membranes (the outer cover). When they are put on the skin in the form of a cream, they help to seal the spaces between the dead cells in the outer skin layer (stratum corneum). This helps the skin to retain moisture better, and that’s useful for dry skin or patients with eczema.
Coenzyme Q-10 – Found mostly in the mitochondria (energy factories) of cells, it is a natural antioxidant. While positive effects of oral supplementation have been shown for other organ systems, there is no proof that putting it in low concentrations in skin care products has any effect that is superior to current products like other antioxidants or retinoids (Vitamin A cousin). However, the marketing is potent.
Copper Peptide – Products containing this compound are interesting because they contain 3 amino acids (tripeptide) bound to a copper molecule. They were originally studied in rats and found to improve wound healing. Studies of wound healing in humans haven’t been as impressive yet. Several studies show that, in skin creams, it may perform as well as Vitamin A creams (retinoids) or Vitamin C but the studies were small and sometimes performed by doctors being paid by the company. In my opinion, the jury is still out.
DNA Repair – The idea that something can repair damage to our DNA caused by environmental insults including excess sun/UV. So far, more marketing than reality in skin care products.
Emollient – This is just another word for moisturizer. Used to correct dryness and scaling of the skin by increasing hydration, preventing moisture loss, or both. The effects of moisturizers are temporary, but over time and used consistently, they make a significant difference in the appearance of skin.
Exfoliants – Skin care products that break down and remove the dead, keratinized cells that naturally build up on the skin’s surface.
Glycolic Acid – A type of alpha hydroxy acids that removes part of the outer dead layer of skin (stratum corneum). Helps to unclog pores and create a smoother skin surface (glow). It may also stimulate some collagen production in the upper layer of the dermis. Lotions with glycolic acid act as an exfoliating agent.
Green Tea Extract – An antioxidant in the flavenoid/polyphenol group. While the benefits of green tea are known, there is some limited but intriguing evidence that topical preparations with a high enough concentrations may be beneficial as an antioxidant, and therefore anti-aging. I don’t know of any studies in skin that give evidence for an anti-skin cancer effect for these products.
Growth Factors – Also called cell growth factors. These are made from the liquid media that is growing very young skin cells (fibroblasts) in the lab. These fibroblasts make a variety of growth factors that fuel the growth of healthy, young skin. The theory is that applying these cell growth factors is like fertilizing your skin. The first and most well-known of these anti-aging products was TNS.
Hyaluronic Acid – An acid that occurs naturally in the skin and helps to retain moisture especially in the spaces between cells. Hyaluronic acid serum and hyaluronic creams are used in moisturizers and other skin care products to lubricate and protect the skin. They are also the main component of hyaluronic fillers like Restylane and Juvederm.
Hydroquinone – This chemical has become controversial in recent years. Often referred to as a bleaching cream it really doesn’t bleach anything. It acts by turning off a key enzyme in the production of pigment (melanin) in the skin. It is found as a skin care ingredient in a 4% concentration in prescription creams like Triluma but can be specially compounded at higher concentrations. In drugstore products, it is usually in a 2% concentration. It promotes the growth of cancers in mice if fed to them in high enough concentrations. It’s hard to know what this means for humans. Don’t use it if you are pregnant.
Kojic Acid – A mild, skin lightening ingredient used in skin creams, especially in Asia. It is a product of a fungus and a byproduct of the fermentation process used to make rice wine. It is not as effective as hydroquinone, unfortunately.
Peptides – The building blocks of proteins, peptides are a string of amino-acids. Used in skin creams, they have still NOT been proven to have an effect equal to the gold standard, retinoids. I do not know of any controlled, double-blinded studies to support the marketing claims. It’s difficult to know yet if these compounds will prove to make visible changes in skin as skin care ingredients.
Retinoids, Retinols, Retinyl Palmitate – They increase skin cell turnover, normalize cells damaged by UV radiation, and induce collagen formation among many other things. Derived from vitamin A, retinoids and retinols are also highly effective in treating acne. Retin-A and Renova are prescription products you can get from your dermatologist. Still the gold standard for anti-aging creams. They reduce wrinkles and fine lines over time, reduce brown spots and have been proven to help prevent the formation of precancerous growths (actinic keratoses). There is 20 years of research to support these claims.
Salicylic Acid – Effective treatment for skin prone to breakouts and acne. This common skin care ingredient is found in both washes and lotions. It is a beta-hydroxy acid. Like alpha hydroxy acids, salicylic acid is helpful in acne treatment to prevent formation of comedones (blackheads and whiteheads). It is also a mild exfoliant.
Shea Butter – The vitamin concentrations found in most commercial shea butter preparations are negligible, but it is an excellent moisturizer.
Silicone Derivatives – Ingredients in moisturizers that sit on the surface of the skin and lock in moisture without clogging pores and causing breakouts. They also give the skin a soft and smooth texture.
Vitamin C (Ascorbic Acid) – An antioxidant which protects skin from the sun by neutralizing free radicals. Vitamin C also promotes some collagen production. This may reduce the appearance of fine lines slightly. Lastly, vitamin C serums have been proven to reduce skin discoloration due to sun damage. Other forms of Vitamin C serum and Vitamin C acid include L-Ascorbic Acid, Magnesium Ascorbyl Phosphate, Ascorbyl Palmitate, Ester-C, and several others. The most effective Vitamin C formulations are serums containing 15-20% L-ascorbic acid. Overall, Vitamin C, in the right concentration, is one of the best topical antioxidants available.
Vitamin E – An antioxidant used to prevent free radical damage which protects the skin from the sun damage. Its main effect in serums/creams is to stabilize and augment the antioxidant activity of Vitamin C.