Before you invest in a new product or treatment, it pays to do your homework. Curious about common skincare terms like “non-comedogenic” or “botanical skincare”? Looking for information about acne, exfoliation or spider veins? The Skincare-News Glossary can help. Educate yourself on everything from antioxidants to zinc oxide in our handy guide to skincare lingo.
Acids: Ingredients used in skincare to exfoliate the outer layer of skin; these can include alpha hydroxy acids, like lactic acid or glycolic acid, and beta hydroxy acids, like salicylic acid.
Acne: This condition can occur in people of all ages — teens, adults and women going through menopause. Acne occurs when dead skin cells and sebum mix with bacteria, causing pimples, cysts, blackheads or whiteheads. Over-the-counter and prescription treatments can help, as well as oral prescriptions.
Acne cosmetica: Acne that’s caused when makeup builds up on the skin, clogging the pores and leading to breakouts.
Acne scars: Discoloration that lingers after an acne breakout has cleared; can be temporary or permanent. See also: post-inflammatory hyperpigmentation; PIH.
Acupuncture: A type of Chinese medicine that uses small needles to treat various physical and emotional ailments. Proponents of cosmetic acupuncture (usually for acne or aging) believe it has a dramatic impact on the skin, while critics suggest sticking to traditional treatments.
Age spots: See sun spots
Alcohol: Many types of alcohol are used in skincare products, and it’s a common misconception that all of them are drying to the skin. Fatty alcohols, such as cetyl alcohol and stearyl alcohol, actually improve the texture of skincare products without stripping the skin of moisture.
Allergic contact dermatitis: A strong reaction to beauty products or jewelry that usually results from a specific preservative, material or fragrance. Symptoms are noticeable anywhere from a few hours to a week later, and can be severe enough to include swelling or water blisters. See also: beauty allergies.
Aloe vera: A soothing plant ingredient that moisturizes dry skin and improves minor skin irritations, such as sunburn.
Alpha hydroxy acids: Exfoliating acids that can come from fruits, milk or sugar cane. Lower strengths appear in skincare products to treat fine lines, wrinkles, age spots and dull skin. Higher strengths are used by professionals in chemical peels to rejuvenate the skin.
Antioxidants: Protective ingredients that prevent free radicals from damaging and aging the skin; these include vitamin C, coenzyme Q10, pomegranate, idebenone and alpha lipoic acid. See also: free radicals.
Argireline: See peptides
Ascorbyl palmitate: The fat-soluble and more stable form of vitamin C; also known to be less irritating. See also: vitamin C
Athlete’s foot (Tinea Pedis): A foot infection caused by a fungus found in warm, moist environments like the gym or locker room. Treatments include ointments, sprays and powders. See also: jock Itch (Tinea Cruris)
Autologous fat transplantation: A minimally invasive anti-aging procedure. During the procedure, a doctor removes fat from one area of the body and injects it into another area to smooth wrinkles. See also: microdermabrasion; chemical peels
Benzoyl peroxide: An acne-fighting ingredient that kills P. acnes bacteria on the skin’s surface while also exfoliating the skin and drying excess oil. Benzoyl peroxide can be very drying and is best for oily or combination skin types.
Beta hydroxy acids: See salicylic acid
Blackheads: Clogged pores that are common on the nose, cheeks and forehead. Blackheads appear when excess oil becomes trapped in the pore and mixes with dead skin cells and bacteria. Blackheads get their black/brownish color when exposed to the air.
Body acne: Breakouts that occur on the chest, arms or back. This type of acne can be more difficult to treat as the skin is often thicker and more resistant to typical acne-fighting ingredients, and may need stronger treatments.
Body wraps: A spa treatment that includes exfoliation and a full-body mask treatment. Body wraps aim to cleanse and hydrate the skin from head to toe.
Botanical skincare: Products that use plant-derived ingredients shown to be beneficial to the skin.
Broad-spectrum sun protection: When this is listed on a sunscreen or sunblock label, it means that the product protects your skin from both types of UV rays: UVA (the aging rays) and UVB (the burning rays).
Bronzer: A powder, cream, gel or liquid that adds a sun-kissed glow to the complexion. You can also find pink and peach-colored shades that create a more natural-looking appearance, even for pale complexions.
Bruises: After an injury, torn or ruptured blood vessels cause blood to leak underneath the skin, causing that telltale purplish or bluish discoloration of a bruise. It can take several weeks for a bruise to heal completely, but over-the-counter treatments can help speed up this process.
Caffeine: While caffeine in beauty products doesn’t have the same punch as your morning coffee, it’s increasingly found in everything from lip treatments and eye cream to moisturizers and rosacea treatments. The key is in caffeine’s ability to constrict blood vessels.
Cayenne pepper: An ingredient that helps to stimulate blood circulation.
Cellulite: Despite common misconceptions, genetics, age and lifestyle can all contribute to cellulite. It’s impossible to eliminate cellulite but you can diminish its appearance with certain lifestyle changes and topical treatments designed to increase circulation.
Ceramides: Found naturally in the body, ceramides are fats that help the skin retain moisture. Synthetic versions are used specifically in anti-aging products because of ceramides’ ability to “plump” the skin.
Chemical peel: Professional treatments that use high concentrations of alpha hydroxy acids to dissolve dead skin cells and accelerate cell turnover, revealing a brighter and healthier complexion. Mild peels are helpful for acne or fine lines; stronger concentrations are used for brown spots and deep wrinkles. While these peels are effective, they’re also potent and should only be administered by a trained professional.
Coenzyme Q10 (CoQ10): This antioxidant defends the skin from free radicals and staves off wrinkles and skin damage. It’s found in both oral supplements and topical treatments, such as eye creams and facial moisturizers.
Coffeeberry: An antioxidant powerhouse that comes from the bright red fruit of the coffee plant. It’s said to have more anti-inflammatory and antioxidant properties than green tea, blueberries and other antioxidants.
Collagen: This protein is naturally found in the skin, and works with another protein — elastin — to support the skin’s structure and prevent it from sagging. Collagen gives skin its youthful appearance and keeps it plump and supple. With age, collagen production slows down and skin starts to sag, develops lines and wrinkles and gets drier. Some topical treatments and injectable fillers can help.
Combination skin: Oily skin in the T-zone of the forehead, nose and chin with cheeks prone to dryness. Combo skin types might want to seek out products designed to treat both oily and dry areas. Another option is to use separate products for each area.
Concealer: Comes in varying shades to cover blemishes, under-eye circles, redness and discoloration. Cream and powder formulas come in a wide array of colors to blend seamlessly with your complexion.
Contact dermatitis: A skin reaction caused by exposure to items such as jewelry, cosmetics or household cleaning products. See also: Allergic contact dermatitis; irritant contact dermatitis
Cool skin tones: Pink or blue undertones that look best in blue-based makeup colors, such as raspberry, burgundy, silver, gray and emerald green.
Couperose: A skin condition characterized by red, flushed skin that’s prone to dryness and sensitivity. Environmental and lifestyle triggers cause the blood vessels to expand and dilate. These include: hot drinks, spicy foods, extreme temperatures and stress.
Crow’s feet: Fine lines or wrinkles around the eyes that form as a result of sun exposure, smoking, the natural aging process and repetitive movements like smiling, frowning or squinting.
Cystic acne: A severe form of acne characterized by blemishes that form deep below the skin’s surface. Whiteheads and blackheads are common, along with the swollen, irritated cysts. A dermatologist must treat cystic acne because it’s so severe and can cause deep, pitted scars.
Dermatologist-recommended (or dermatologist-tested): While this phrase is used on countless skincare products, it actually doesn’t mean much. Any company can claim that their formula is dermatologist-recommended (or tested) — even if only one dermatologist has tried the product.
Dermis: The skin’s middle layer and the location of collagen and elastin, as well as oil glands. See also: epidermis, hypodermis
Dimethicone: This silicone-derivative is widely used in personal care products, including shampoo, conditioner, lotions and cleansers. Its main purpose is to smooth and condition the hair and skin. Plus, because dimethicone is not water soluble, it creates a moisturizing, protective coating on both your locks and skin. It’s also added to products like lipstick to make the texture smoother.
Eczema: A skin condition characterized by dry, itchy, red, swollen skin that can be extremely uncomfortable. Eczema is problematic in children, who have a hard time resisting the urge to itch and can develop infections.
Eco-conscious skincare: Beauty products that don’t hurt the environment, aren’t created using pesticides and don’t contain irritating chemicals; many of these products are also free from artificial fragrances and dyes and use biodegradable packaging.
Elastin: A protein found in the skin that helps it bounce back after being stretched and prevents skin from sagging. While most formulas focus on boosting collagen, retinoids may affect elastin as well as collagen.
Emollients: These are softening and soothing ingredients, which include: lactic acid, shea butter, petrolatum, lanolin, petrolatum, cyclomethicone, dimethicone copolyol, glyceryl stearates, propylene glycol linoleate, silicone, mineral oil and plant oils.
Emotional aging: Skin problems that result from stress and emotional troubles.
Epidermis: The outermost layer of the skin, which is where dead skin cells are shed. Melanin — the pigment that determines skin color — is also produced here. See also: dermis; hypodermis
Epilation: This at-home hair removal method uses a hand-held electrical device to remove hair from the root, rather than just cutting it off at the skin’s surface. Results last longer than shaving, but the process is time-consuming and can be painful.
Essential fatty acids (EFAs): Found in fish and several types of nuts, EFAs like omega 3, 6 and 9 help to moisturize the skin and decrease inflammation. You can also find EFAs in topical and supplement forms.
Essential oils: Plant extracts that contain numerous benefits when applied to the skin, including: killing bacteria, soothing inflammation, disinfecting the skin, reducing redness and possibly firming and toning the skin.
Eucalyptus: An antiseptic ingredient that can soothe muscle pain as well as help with acne and oily skin.
Exfoliation: This process removes dead skin cells from the skin’s surface. Some exfoliants use physical beads or particles to scrub off dead skin cells, while others use chemical ingredients like enzymes or alpha hydroxy acids to dissolve and break up dead cells.
Eye cream: Designed to be less irritating and more moisturizing than facial cream. In addition to hydrating the skin around the eyes, eye creams can also diminish dark circles, reduce puffiness and smooth fine lines.
Facial: Usually a pampering treatment that also treats specific skin problems. Some examples include: soothing facials for rosacea, clarifying acne facials, hydrating anti-aging facials and intensive facial peels. See also: Pore extraction
Facial exercises: Proponents of this new “workout” believe that facial movements like squinting and frowning help to strengthen facial muscles and lead to younger-looking skin. But facial exercises are actually useless and can even backfire: Experts believe that they lead to more wrinkles and fine lines.
Facial steaming: Helps to soften skin, open pores and bring impurities to the skin’s surface. Often used before other facial treatments like masks.
Fair trade skincare: Skincare products that contain ingredients that are produced according to fair trade standards, such as ensuring humane working conditions and creating products without harming the environment. See also: eco-conscious skincare
Ferulic acid: An antioxidant naturally found in plants. It provides protective benefits against free radical and UV damage. Ferulic acid is typically combined with vitamins C and E, because it stabilizes these antioxidants and boosts their ability to neutralize free radicals. See also: antioxidants
Feverfew: Protects skin from free radicals plus UV-induced redness and inflammation. It may also stimulate repair processes in skin cell DNA. When used in skincare products, feverfew is purified and becomes feverfew PFE, or parthenolide-free extract.
Fractional resurfacing: A professional cosmetic laser treatment using a special light frequency, in which microscopic beams penetrate the skin. By heating both the epidermis (outer layer of skin) and the dermis (second layer), fractional resurfacing removes the rough, damaged layers of skin. Factional resurfacing is ideal for treating age spots, discoloration, scars and UV damage. There’s minimal pain, short recovery time and long-lasting results.
Free radicals: Unstable molecules that try to steal electrons from stable molecules, creating a chain of other unstable molecules that can damage the skin, leading to wrinkles and aging skin. Environmental factors like pollution, UV rays, smoke and pesticides all contribute to create skin-threatening free radicals. See also: Antioxidants
GABA: This anti-aging ingredient is naturally produced in our bodies, and is related to nerve and muscle function. When used in skincare products, GABA ( gamma-aminobutyric acid ) helps relax the muscles that cause lines and wrinkles to form, making it ideal for anti-aging formulas that treat expression lines and crow’s feet.
Glycerin: An ultra-moisturizing ingredient in the humectant family, which attracts moisture into the skin. Glycerin is very common in soaps and other moisturizing skincare products.
Green tea: While all teas have valuable ingredients, green tea is hailed as one of the most antioxidant-rich drinks. Topical green tea also has tons of benefits, and you’ll find it in an array of skincare products. Some research has shown that green tea protects the skin from sun damage by neutralizing free radicals and diminishing inflammation. Plus, it may slow down the aging process.
Heat rash: Clusters of small red pimples or blisters on the skin caused by excessive sweating due to elevated body heat or exposure to high temperatures. Heat rash can affect individuals of all ages but is most common in young children.
Hives: A sudden outbreak of pale red bumps on the skin that’s usually the result of an allergic reaction. Hives may itch, burn or sting and can develop anywhere on the body. Size may range from less than one inch to several inches in diameter.
Humectants: Ingredients designed to draw water from the dermis to the epidermis. They also draw moisture from the surrounding atmosphere into the skin when humidity is above 70 percent. Humectants, thereby, prevent dryness, cracking, chapping, irritation and skin build-up. Common humectants are glycerin, hyaluronic acid, propylene glycol, sorbitol and urea.
Hyaluronic acid: Naturally occurs in the body and is found between collagen and elastin fibers. Hyaluronic acid retains moisture; promotes a soft, supple texture; affects inflammation and immune activity; and plays a role in skin repair. With age, hyaluronic acid levels decrease. When it appears in skincare formulas, hyaluronic acid hydrates the skin, but doesn’t have the same anti-aging benefits as it does when it occurs naturally in the body. It’s also found in synthetic forms in injections (such as Restylane), which instantly create a more youthful appearance.
Hydrocortisone: A topical treatment available over the counter that can help with itchiness and irritation.
Hydrogen peroxide: This household staple, often used for disinfecting wounds, is also found in skincare products. Because hydrogen peroxide is a lightening agent, it’s included in hair bleaching products, teeth whitening treatments and facial formulas used to fade scars and acne marks.
Hydroquinone: This chemical ingredient is regarded as one of the most effective skin lighteners on the market. It works by blocking the enzyme tyrosinase, which is necessary to create melanin (the pigment that causes skin darkening). There are some safety concerns about hydroquinone, but many experts still consider it to be the gold standard in skin lightening.
Hyperpigmentation: A darkening of the skin in areas where melanin production increases. Sun exposure is a major cause of hyperpigmentation, but wounds or inflammation caused by acne or injury can also cause temporary or permanent hyperpigmentation. Sun spots or liver spots are more permanent, but many lightening treatments can help. Larger areas of hyperpigmentation can occur during pregnancy, known as melasma.
Hypoallergenic: Products with this label are thought to be less likely to cause allergic reactions and irritations. However, the Food and Drug Administration (FDA) doesn’t regulate how this term is used. That means it’s up to the manufacturer to decide when to use this label, making it more of a marketing tool than a helpful guide for consumers.
Hypodermis: Subcutaneous tissue that makes up the skin’s bottom layer. It’s the skin’s protective layer and the location of hair follicles. See also: Epidermis; dermis; subcutaneous tissue
Idebenone and idebenol: Similar chemically to coenzyme Q10, idebenone is said to fight free radicals and reduce lines and wrinkles. Idebenol, which is related to idebenone, has similar results, but experts believe it’s less powerful. See also: Coenzyme Q10; free radicals; antioxidants
Impetigo: A common bacterial infection of the skin resulting in blisters that may occur anywhere on the body, including the face, neck and hands. Impetigo is contagious and very common in children.
Irritant contact dermatitis: An uncomfortable short-term reaction like itching or burning that results from using a new cosmetic product. See also: Beauty allergies
Itchy skin: See pruritus
Jojoba oil: Comes from the jojoba plant, which grows in the desert. It’s naturally antibacterial and helps exfoliate, soften and hydrate the skin (and hair). You’ll find jojoba oil in all types of skin and hair products. You also can purchase the pure oil to use as a moisturizer.
Keratosis pilaris: A harmless but frustrating skin condition that affects up to 50 percent of the population. It occurs when the protein keratin blocks hair follicles, creating small white bumps on the backs of the upper arms, thighs, buttocks and sometimes the face. Treatments include exfoliating ingredients like alpha hydroxy acids that unclog the pores.
Kojic acid: An ingredient found in skin-lightening treatments that inhibits melanin production and may be just as effective as hydroquinone.
L-ascorbic acid: See vitamin C
Lactic acid: An alpha hydroxy acid that’s produced from milk, and has both moisturizing and exfoliating properties. It’s found in many over-the-counter and prescription moisturizers. See also: Alpha hydroxy acids
Laser hair removal: A method of hair removal that applies low energy beams to unwanted body hair for permanent elimination. Laser hair removal can treat a large area, making it a cost-effective way to remove unwanted hair.
Laser resurfacing: A skin treatment that uses various wavelengths to remove damaged skin, and can improve a variety of skin concerns, including: acne, rosacea, fine lines, wrinkles, sun spots and cancerous growths.
Lavender: This soothing essential oil boasts many good-for-you properties: It’s naturally anti-i nflammatory, antibacterial and anti-fungal. When used topically either as an oil or in skincare products, it has a calming and healing effect.
LED light therapy: Uses light-emitting diodes to treat skin that’s acneic, scarred, aging or sun damaged. LED light therapy stimulates cell turnover and the production of collagen to help skin appear younger and healthier.
Lemon: A naturally antibacterial and gentle cleanser. Lemon may also reduce oil and acne, and rejuvenate tired skin. It’s also a natural lightening ingredient.
Lipids: Proteins that dictate the texture and look of your skin, depending on their organization.
Liver spots: See sun spots
Macadamia nut oil: An oil that contains skin-healthy palmitoleic acid, which is naturally found in the sebum of youthful skin. Macadamia nut oil is naturally emollient and great for all skin types, including dry and mature skin.
Massage therapy: A massage can help boost circulation — which might lead to clearer pores — exfoliate the skin and improve skin texture.
Medical spas: A facility that offers cosmetic and medical treatments like Botox, laser treatments and chemical peels in addition to traditional spa treatments like massages and manicures. If you’re interested in undergoing a procedure at a medical spa, make sure to check out the facility’s credentials and ensure that you’re consulting a reputable professional.
Melanin: The pigment produced by your body — by cells called melanocytes — that determines skin color. For instance, dark-skinned people have more melanin than light-skinned people.
Melanoma: One of the most serious forms of skin cancer, with more new cases diagnosed every year than all other cancers combined. Symptoms include moles that change in size, shape, color and texture or become painful. When diagnosed early, melanoma can be cured, but advanced cases can be fatal.
Menopause: The phase in a woman’s life after which she no longer has menstrual periods, typically around age 50. Because of hormonal changes, menopause may bring on skin- or hair-related symptoms, such as skin dryness, acne, facial flushing, sweating, hot flashes and hair loss.
Microdermabrasion: A skin treatment in which finely ground micro aluminum dioxide crystals are applied and spread over the face with a special hand-held device. These crystals help to slough away the outermost skin layers and dead skin cells, reveal a fresher complexion and reduce the look of lines and pores. Unlike other treatments or procedures, microdermabrasion requires no downtime to heal or recover.
Mineral makeup: Makeup made from fine-textured, earth-based minerals, like zinc oxide, mica or titanium dioxide. Often, mineral makeup is free of potentially irritating colors, chemicals, fragrances and preservatives, making it ideal for rosacea, acne-prone or sensitive skin. Common formulations are powder-based foundations and blushes.
Mineral Oil: A petroleum-based ingredient used in skincare products and makeup for more than a century. It creates a barrier wall to prevent water loss from skin, and has a moisturizing effect. However, it may clog pores or cause acne for some individuals.
Moisturizer: Gels, lotions or creams designed to hydrate the skin by building up skin’s barrier to better retain water. Available for different skin types, moisturizers can be oil-based or water-based, with common ingredients like petrolatum, dimethicone, glycerin and hyaluronic acid.
Moles: Raised, textured dark brown or black growths on the skin, caused by cell clusters clumping together and producing melanin, or pigment. Moles can be present at birth, and most develop before age 20. New mole development or changes in existing moles should be examined by a dermatologist, and could possibly indicate skin problems, such as skin cancer. See also: Melanoma; melanin
MRSA or Methicillin-Resistant Staphylococcus Aureus: A serious infection caused by staph bacteria that enters the body via cuts or other openings, causing redness, bumps, blisters, pimples or pus-filled abscesses. MRSA can also spread to the bloodstream or vital organs and can be fatal because it’s resistant to many types of antibiotics. MRSA can be acquired in healthcare facilities or via skin-to-skin contact and shared personal belongings. It’s especially common in very young children, individuals with weak immune systems and athletes.
Natural Moisturizing Factor (NMF): A group of compounds found in the outer layer of the epidermis that helps to retain moisture. These compounds take moisture from the atmosphere and combine it with their own moisture in the skin.
Natural skincare: Tons of products claim to feature “natural” ingredients; unfortunately, because the term “natural” isn’t regulated by the Food and Drug Administration (FDA), it’s difficult to confirm a company’s claims. Also, keep in mind that there’s no scientific evidence that natural ingredients are safer or superior to synthetic ingredients. That’s why it’s wise to do your homework when deciding between natural and synthetic options. Also, be sure not to confuse “natural” skincare with “organic” formulas.
Niacinamide: See vitamin B
Noncomedogenic or nonacneic: These labels mean that products don’t appear to clog pores or cause breakouts — an ideal choice for oily or acne-prone skin. However, everybody reacts differently to ingredients, so be aware that these labels are not 100 percent reliable.
Occlusives: Ingredients that slow down the evaporation of water from the skin, and appear in moisturizers, including: beeswax, caprylic/capric triglycerides, cyclomethicone, hydrogenated castor oil, mineral oil, lanolin, petroleum, petrolatum, silicone, dimethicone and vegetable oils (like avocado or olive oil).
Oil-free: A label that describes a product that isn’t oil-based, and thereby shouldn’t clog pores. These products are the best types for oily and combination complexions. Oil-free formulas include moisturizers, sunscreen, foundation and body lotion.
Olive oil: A rich, nourishing oil that can be used straight from the bottle, or purchased in a variety of skincare products. Olive oil is suitable for dry complexions, and not recommended for acne-prone skin.
Organic: Agriculture that’s conducted according to standards that minimize the use of fertilizers and chemical pest control. Products and ingredients derived from organic agriculture support the use of renewable resources and the conservation of soil and water to enhance environmental quality. In order to bear the USDA organic seal, skincare formulas must contain 95 percent organic ingredients. See also: Natural skincare
Parabens: Chemical compounds used as preservatives in personal care and beauty products to extend shelf life by preventing the growth of fungi, mold and bacteria.
Peppermint: A naturally antiseptic ingredient that has cooling and soothing properties. See also: Essential oils
Peptides: Strands of amino acids that naturally occur in skin, providing it with strength and structure. As a skin care ingredient, peptides may have some anti-aging benefits, such as reducing the appearance of fine lines and wrinkles.
Permanent makeup: Uses tattooing to apply permanent color to the skin to resemble makeup.
Photosensitivity: A condition in which skin has increased sensitivity to UV light. Photosensitive skin is more likely to burn, blister and may have an elevated risk of developing skin cancer with prolonged sun exposure. Photosensitivity can be caused by medications, some skincare ingredients or certain medical conditions.
Pimples: See acne
Polyhydroxy acids: A new generation of alpha hydroxy acids (AHAs) that’s gentler on the skin than AHAs. Also known as PHAs, polyhydroxy acids boast moisturizing benefits and enhance the skin’s barrier function. They’re frequently used in anti-aging and acne treatments. PHAs are also safe on sensitive skin (like rosacea) and post-cosmetic procedures.
Pores: Tiny openings on the skin’s surface that allow sebum, the skin’s natural oil, to exit the skin. Healthy pores are clear and small. However, when pores are clogged with dead skin and debris, they can stretch and become enlarged, often turning into blackheads or whiteheads. See also: Acne, blackheads, whiteheads; cystic acne
Pore extraction: A process performed by an esthetician or other skincare specialist that removes blackheads and other impurities that can build up in the pores. See also: Facials
Post-inflammatory hyperpigmentation (PIH): Discoloration after an acne breakout that can last up to 18 months. PIH is not permanent, but lightening treatments can help it fade faster. See also: Acne scars
Pruritus: This is an umbrella term for itchy skin that can occur for a variety of reasons: skin conditions like eczema or hives, seasonal dry skin or even medical conditions. There are multiple topical treatments available to soothe the itch, but when itchy skin is severe or the cause is unknown, it’s important to see a doctor. See also: Hives, eczema, allergic contact dermatitis
Product expiration: Contrary to popular belief, makeup and skincare products do expire, and it’s important to periodically check the expiration dates listed on the packaging. If there’s no date listed, look for signs that the product has expired, such as changes in smell, consistency or color.
Psoriasis: A common autoimmune skin condition that causes redness, flaking and silvery patches called scales. Psoriasis most often occurs on the elbows, knees and torso, but can appear anywhere on the body.
Restylane: A clear hyaluronic acid gel that’s typically injected into the face to smooth moderate to severe wrinkles and folds, especially around the nose and mouth. A doctor must administer Restylane injections. See also: Hyaluronic acid
Retinoids: Derivatives of vitamin A, these prescription-strength topical treatments are the gold standard in anti-aging, because they build collagen, reduce wrinkles and fine lines and improve overall skin tone and texture. Retinoids are also highly effective in unclogging pores and treating acne. Because they’re so potent — and can cause irritation and dryness — it’s crucial to work with a dermatologist to find the best way to make a retinoid formula part of your regimen.
Retinol: Also a vitamin A-derivative, retinol is less potent than retinoids, making it ideal for people with sensitive skin who can’t tolerate retinoids. Retinol is available over the counter. You can also use a retinol formula before retinoids to let your skin gradually get accustomed to vitamin A.
Rosacea: A chronic skin condition that causes inflammation, redness, red lines (called telangietctasias), swelling or pimples across the forehead, chin, cheeks and nose. Rosacea most often affects adults between the ages of 30 and 50 and individuals with fair skin.
Rosemary: This essential oil is naturally antiseptic, astringent and antioxidant; it also helps to condition hair and relieve tension.
Salicylic acid: An effective ingredient derived from white willow bark that’s used to treat acne and encourages exfoliation of dead skin cells.
Scalp folliculitis (scalp acne): A contagious scalp condition characterized by inflammation and itching.
Sebum: A natural moisturizer secreted by the sebaceous glands, which dictates whether your skin is dry or oily.
Sensitive skin: Skin that’s highly affected by environmental factors such as climate, products, foods, exercise, pollution, smoke and UV rays.
Serum: An ultra-concentrated formula that penetrates more deeply into the skin and delivers effective active ingredients.
Shea butter: A moisturizing ingredient that’s especially helpful for extra-dry skin. Aside from being a super-star hydrator, shea butter is also full of antioxidants and can be used to soothe sunburned skin.
Silicone: A shiny, nonreactive substance that comes from silica, or sand. A common ingredient in hair care products, silicone helps to seal in moisture, improve split ends, condition strands and add shine.
Silk: A protein that requires costly procedures to manufacture but can help hair look shinier.
Sirtuins: A class of proteins that may have anti-aging advantages . Studies suggest that sirtuins may reduce cellular aging by enhancing the ability of cells to repair DNA and produce protective antioxidants.
Skin tones (warm or cool): The undertones of your skin that characterize your complexion. These categories are often used to select cosmetic colors and shades that naturally complement your complexion. See also: Warm skin tone, cool skin tone
Sodium hyaluronate: Comes from the salt of hyaluronic acid, a natural substance in the body. This hydrating ingredient attracts water to the skin and keeps it moisturized and supple.
Sodium lauryl sulfate (SLS): A surfactant that commonly appears in shampoos, soaps and other products because of its abilities to create lather and lift away dirt, oil and other impurities from hair and skin. Despite criticisms that SLS is dangerous, it is considered safe for use in cosmetic products.
Stretch marks: Bands, stripes or lines on the surface of skin that are caused by rapid growth or certain diseases. Stretch marks occur most often on the breasts, hips, thighs, buttocks and around the abdomen.
Subcutaneous tissue: The skin’s protective bottom layer. See also: Hypodermis
Sulfur: A centuries-old treatment for acne, rosacea, dandruff and other skin conditions. It works by decreasing oil production and promoting peeling of dead skin cells, thereby preventing clogged pores. However, sulfur can smell like rotten eggs — though most products aren’t so bad anymore — and may cause skin irritation, redness or dryness.
Sun allergy: See photosensitivity
Sun spots: Hyperpigmentation that results after excess sun exposure causes the body to create too much melanin. See also: Melanin
Surfactants: A chemical that reduces the surface tension between oil and water molecules. As the main active ingredient in shampoos and facial washes, surfactants condition and cleanse by lifting impurities out.
T-zone: Refers to the areas of the forehead, nose and chin; individuals with combination skin will notice that their T-zone is typically oilier and prone to acne and clogged pores, while the cheeks are on the dry side.
Tea tree oil: An antiseptic and anti-inflammatory ingredient that’s used in everything from skincare products to toothpaste; tea tree oil can be helpful in treating acne and a number of other conditions.
Thread lift: An outpatient cosmetic procedure that’s less invasive than a facelift. During a thread lift, doctors place plastic sutures below the skin to strengthen tissue for a more youthful look.
Tinea pedis: See athlete’s foot
Titanium dioxide: A mineral that shields skin from ultraviolet rays by blocking them. It commonly appears in sunblocks, and doesn’t irritate the skin.
Toner: A liquid or gel used after cleansing to refresh the skin and remove excess oil and leftover impurities. Toners for dry skin contain soothing ingredients like rosewater, while toners for acne-prone skin contain ingredients like witch hazel or acne-fighting ingredients to unclog pores. Some experts say that toner is unnecessary, but it really depends on your preference.
Triclosan: Commonly used as an antibacterial agent in hand sanitizers and acne products. There are some safety concerns about triclosan but no conclusive evidence as of yet.
Ubiquinone: See Coenzyme Q10
Under-eye circles: Bluish purple circles that form under the eyes, caused by thin skin, excess pigmentation or melanin, fluid build-up or heredity. Under-eye circles can be accompanied by puffiness or swelling. Treatment options include cold tea bags to reduce puffiness, in-office laser procedures and hydroquinone or kojic acid creams to minimize discoloration.
Urea: A waste product that surprisingly offers a variety of skin benefits, including: retaining moisture, replenishing and strengthening the skin, and improving the penetration of active ingredients.
Uticaria: See hives
UVA and UVB rays: Ultraviolet A (UVA) and ultraviolet B (UVB) rays are invisible waves of energy from the sun that cause skin damage, sunburn, premature aging and skin cancer.
Varicose and spider veins: Enlarged dark, purple or blue veins that appear near the surface of the skin. Both varicose veins and spider veins occur when blood leaks into and accumulates in the vein due to weakened valves.
Vitamin A: A powerful and well-researched skincare ingredient that effectively prevents and reverses signs of aging and acne. It neutralizes free radicals, stimulates collagen synthesis and accelerates cell turnover. Food-wise, being deficient in vitamin A can also affect the skin because this vitamin is vital for normal cell functions. A deficiency in vitamin A can make a person susceptible to dryness, wrinkles and sensitive skin. See also: Retinoids; retinol
Vitamin B: A group of vitamins — such as niacin, thiamine, riboflavin, biotin and folic acid — that provides cells with energy for metabolism and other functions. Vitamin B deficiencies may result in greasy and scaly skin, dryness or irritation, lackluster locks or poor hair growth. Vitamin B is found in many foods, such as grains, cereal, rice and green vegetables, and in supplements. When found in skincare formulas, vitamin B can hydrate and exfoliate the skin. Specifically, a form of niacin, niacinamide has a variety of benefits, including diminishing dark spots, hydrating the skin and repairing UV damage.
Vitamin C: An antioxidant that counteracts harmful free radical effects, decreasing skin damage, and boosts collagen to reduce the look of lines. While it has great benefits, vitamin C is notoriously unstable. When vitamin C is exposed to oxygen, it breaks down, loses its potency and can even create damaging radicals. Look for more stable derivatives of vitamin C, such as ascorbyl palmitate.
Vitamin E: Another antioxidant that strengthens the lipids that compose skin cell barriers, protecting them from free radicals and UV damage and enhancing vitamin C’s antioxidant powers. Vitamin E may also prevent vitamin C from oxidizing and spoiling when the ingredients are combined.
Vitamin K oxide: A skin care ingredient that strengthens capillaries and prevents them from leaking to improve the appearance of discoloration, bruising, spider veins, under-eye circles and purpura (purple spots on the skin).
Warm skin tones: Yellow or orange undertones that look best in yellow-based makeup colors, such as tan, honey, wheat, cream and beige.
Warts: A hardened growth on the skin, caused by a viral infection, that most often occurs on the hands or feet. Without treatment, most warts disappear within months or years.
Water soluble: Any compound that can be dissolved in water. Water-soluble ingredients are typically mild and are often used in cleansers to moisturize dry skin.
Zinc oxide: A mineral that treats minor skin irritations, including diaper rash, mild burns and chapped skin. Zinc oxide is also commonly used in sunblocks because it blocks or reflects ultraviolet rays, and doesn’t irritate the skin. See also: Titanium dioxide