It’s important to know exactly what you’re applying, it’s also important to maintain perspective on which ingredients that might work for other people doesn't work for us and why. We have built this cheat sheet of skin-care jargon that will help you parse everything from your favorite TikTok haul to the back of your fave skincare bottle.

We've sorted the terms in alphabetical order. If there's anything you think we've left out, reach out to us at to let us know, and we'll do our best to update this list to keep you informed (and, on trend!).


ACNE The three factors in acne breakouts are oil, dead skin cells, and bacteria, and if any of these factors are out of balance, breakouts can occur. Acne is more likely to take place on the skin when experiencing stress, hormonal changes, excess oil production, and slower cell turnover with aging.

ACTIVE INGREDIENT Over-The-Counter (OTC) actives are ingredients regulated by the FDA. Examples are Sun Protection Factor (SPF), Benzoyl Peroxide, Hydroquinone, Sulfur, and Salicylic Acid. The FDA requires that these ingredients submit to and successfully pass clinical testing and subscribe to labeling standards including usage instructions and benefit claims.

ALCOHOL There are different types of alcohol used in cosmetics for different reasons. SD Alcohol stands for 'specially denatured' alcohol, which is designed especially for cosmetics use to evaporate quickly, leaving the active ingredients on the skin's surface. Fatty alcohols are made from fatty acids and can be used as emollients, thickeners, or carrying agents for other ingredients. They attract water to keep moisture in the skin, and can repel water to form a protective skin barrier. They also create a creamy texture.

ALGAE (SEAWEED) Algae is used in skincare to help support natural collagen, reduce visible wrinkles, and ensure moisture balance in the skin. It is considered by some to be the world's most basic yet complete food. Both in the diet and in skincare products, algae can provide vitamins, minerals, trace elements, amino acids and fatty acids that are important for maintaining healthy and youthful skin.

Also called: Pullulan, Pepha Tight, Pepha-Tight, Microalgae, Micro Sea Algae, Algae Extract, Seaweed Extract, Kelp, Sea Kelp

ALGURONIC ACID is exclusively found in Algenist skincare products and is produced by microalgae. Its unique properties create visible skincare results. It has been shown to support natural collagen and elastin, and boost skin renewal to even skin tone and texture.

ALLANTOIN According to, this plant compound is known as a skin soother because of its healing properties; you’ll often find it added to products in order to calm the complexion and lessen irritation.

ALPHA-TOCOPHEROL It may be a mouthful, but it simply means vitamin E. The nourishing vitamin is an antioxidant that neutralizes damaging free radicals.

ALPHA HYDROXY ACID (AHA) AHAs are found in fruits, milk, and sugarcane, according to Specifically, these are glycolic, lactic, and citric acid. AHAs work by breaking apart the glue that holds dead skin cells together to speed exfoliation, notes Paula’s Choice.

ALPHA LIPOIC ACID An antioxidant that protects against free radical damage that ages skin, it repairs damage to smooth lines and improve tone, according to the Cleveland Clinic, which notes that alpha lipoic acid has been dubbed “the miracle in a jar.” It has an antioxidant capacity 40,000 percent stronger than vitamins E and C combined, according to The Ordinary.

AMINO ACID The building blocks of proteins like collagen, some of which help prevent lines and wrinkles from forming, and bolster skin elasticity, according to L’Oréal Paris USA.

ARBUTIN From the bearberry plant, the hydroquinone derivative is used as a skin brightener, notes an article published in 2017 in Maxillofacial Surgery.

ASCORBIC ACID Commonly known as vitamin C. It appears in many anti-aging formulations as a skin protective and repairing antioxidant; it’s also used as a preservative to protect certain cosmetic products from degrading, per Éminence Organic Skin Care.

AVOBENZONE Flip over the bottle of sunscreen and you might find this chemical ingredient. It protects by absorbing UVA rays, according to the Environmental Protection Agency (EPA); UVA radiation contributes to both skin aging and skin cancer.

AVOCADO OIL One of the buzziest ingredients of the moment, avocado’s fatty acids are packed with skin-nourishing vitamins like A, D, and E.

AZELAIC ACID Kills acne-causing bacteria when added to pimple creams; reduces redness and soothes skin when found in gels and foams that treat rosacea, according to Mayo Clinic. Available by prescription and OTC.

BENZOPHENONE Another common chemical UVA-absorbing sunscreen agent. Specifically, the EPA notes, this group includes dioxybenzone, oxybenzone, and sulisobenzone. Some people may find that chemical-based sunscreens are irritating to sensitive complexions, particularly those with benzophenones.

BENZOYL PEROXIDE Used in topical acne washes and creams, BP kills the bacteria that lead to breakouts and reduces inflammation, per the U.S. National Library of Medicine. Warning: It’ll bleach your clothes and towels.

BETA HYDROXY ACID (BHA) BHAs exfoliate dead skin cells from the surface of the skin. Unlike alpha hydroxy acids, BHAs are oil-soluble and can penetrate deeper inside the pores and exfoliate all the dead skin built up inside. An example is salicylic acid.

CAFFEINE According to, caffeine is a plant compound. It nourishes skin and is a common ingredient in under-eye creams and gels because of its anti-inflammatory effects; it decreases puffiness and constricts blood vessels to reduce dark circles.

CAMELLIA SINENSIS LEAF EXTRACT Simply put, this is green tea leaf extract. Added as an antioxidant, hydrator, and fragrance, according to the EWG.

COLLOIDAL OATMEAL Made from oats that have been ground into powder and used in sensitive skin products, these soothe by building skin’s barrier to keep out irritants, and they have anti-inflammatory properties, according to DermNet NZ.

DIETHANOLAMINE DEA for short, it acts as an emulsifier, foaming agent, or pH controller. The EWG flags DEA and related ingredients as a high concern for toxicity. The FDA says that DEA and its related ingredients do not appear to pose a risk to people when they’re used in cosmetics. (They also note that they are formulated into products less frequently today.)

DIMETHICONE Derived from silicon (a naturally occurring element), dimethicone is a moisturizing ingredient that locks water into skin. It's found in creams, lotions, and soaps, according to

ETHYL ALCOHOL Also known as alcohol, according to, it’s found in a range of skin-care products as an astringent or is used to improve the quality of the finished solution (for example its texture or thickness).

FATTY ACIDS Per L’Oréal Paris USA, these are listed under several names in the ingredients list: glycerides, sterols, phospholipids, omega 3, and omega 6. They prevent water loss from skin, so they’re added to moisturizers. They also thicken product formulations as well.

FERULIC ACID According to an article published in 2014 in Wheat and Rice in Disease Prevention and Health, this is an antioxidant derived from rice bran; you'll find this added to anti-aging serums, moisturizers, and youth-boosting treatments, according to the EWG.

FORMALDEHYDE Listed as imidazolidinyl urea or DMDM hydantoin, these ingredients are preservatives. They release formaldehyde “over time to prevent mold and bacteria from growing in and spoiling your products,” according to When used within advised limits, the Cosmetic Ingredient Review (CIR) declares these ingredients safe. The EWG, however, flags them as a potential cancer risk.

FRAGRANCE A variety of chemicals give products their scent, according to the EWG. In some people, they may cause irritation. Those with sensitive skin or conditions like rosacea are advised to choose fragrance-free products.

GLYCERIN As a sugar alcohol, glycerin draws moisture from the surrounding environment and pulls it into skin. Because of its role as a top-notch hydrator, it is the second most used ingredient used in personal care products, according to (No. 1 is water.)

GLYCYRRHIZA GLABRA This is the proper name for licorice. Licorice root extract may be used in products that target pigment problems, per the aforementioned 2017 article in Maxillofacial Surgery. It’s also used as a skin-soothing ingredient.

HYALURONIC ACID A sugar molecule that exists naturally in your body. The anti-aging moisturizer and skin plumper absorbs up to 1,000 times its weight in water. It also may be listed as sodium hyaluronate or potassium hyaluronate, according to

HYDROQUINONE A skin-lightening ingredient that inhibits tyrosine, an enzyme involved in melanin production, according to the American Osteopathic College of Dermatology. It's used to fade conditions like melasma, as well as bleach hyperpigmentation.

KOJIC ACID An alternative to hydroquinone, the fungus-based brightener targets discolorations by inhibiting pigment production, per the Cleveland Clinic.

LACTIC ACID lists this in the category of alpha hydroxy acids (AHAs), and it may also appear as “lactate” (as in calcium lactate or sodium lactate). It’s often found in anti-aging products because it exfoliates to boost brightness and even out tone, and draws water into skin to hydrate.

LANOLIN A waxy substance secreted by sheep, this fatty ingredient is highly moisturizing, according to the EWG.

LYCOPENE Per L’Oréal Paris USA, a skin protecting and repairing antioxidant that is most famously found in tomatoes.

MANUKA HONEY A buzzworthy ingredient, thishoney native to Australia and New Zealand seals moisture into skin, according to L’Oréal Paris USA. It’s also known as an antibacterial and antifungal agent.

METHYLPROPANEDIOL A long name for a basic function; this is included in skin-care products as a solvent. According to the EWG, it doesn’t pose a health risk.

MINERAL WATER “All water contains minerals, which vary depending on the source of the water,” says Joshua Zeichner, MD, the director of cosmetic and clinical research in the dermatology department at Mount Sinai Hospital in New York City. But the mineral makeup matters, he adds. For instance, hard water, which can leave a residue on your hands, per the U.S. Geological Survey (USGS), is high in calcium, an ingredient that can harm the outer layer of your skin, Dr. Zeichner says. Mineral (or “mineralizing”) water found in facial mist, on the other hand, contains selenium, which can provide anti-inflammatory benefits that help calm, soothe, and hydrate angry skin. “Mineral water may be especially useful if you have skin sensitivity or facial conditions like rosacea,” Zeichner says.

PANTOTHENIC ACID Vitamin B5 strengthens skin’s barrier to stop water loss, and is commonly found in lotions, creams, and serums, according to L’Oréal Paris USA.

PARABEN A family of chemicals that are used as preservatives. Multiple types are typically formulated into the product; see methylparaben, propylparaben, butylparaben, and ethylparaben. Parabens can be irritating to some complexions. But the larger concern is that parabens are dangerous and may be endocrine disruptors. The FDA says that there is no information showing that parabens in skin-care and cosmetics are hazardous to health.

PEPTIDES These are chains of amino acids, which are the building blocks of protein. Your skin is made up of proteins, like collagen, and peptides stimulate this collagen production. For that reason, peptides are prominent in anti-aging products.

PETROLATUM This is your standard petroleum jelly. The thick, sticky substance forms a barrier on skin that locks in moisture. Use it to promote healing and treat chapped lips and flaky eyelids, suggests the American Academy of Dermatology (AAD).

PHTHALATES These chemicals — particularly diethyl phthalate (DEP) — are another controversial ingredient. In cosmetics, DEP is used as a solvent in fragrance, and while the Campaign for Safe Cosmetics has flagged them as endocrine disruptors and linked them to cancer, the FDA says there is no established health risk from exposure to phthalates.

RETINOIDS According to the University of Wisconsin in Madison School of Medicine and Public Health, retinoids are a derivative of vitamin A and are used in anti-aging and anti-acne skin products. These, like tretinoin, tazarotene, and adapalene, help enhance collagen production and are available by prescription or in over-the-counter preparations. When it comes to acne, retinoids keep pores clear and reduce inflammation, according to Differin.                                                      

RETINOL An over-the-counter vitamin A derivative, retinol is a weaker form of retinoid. You might see this listed on the package as retinyl palmitate or retinaldehyde.

RHAMNOSE This plant-derived, specialized sugar molecule acts as a messenger to help stimulate cellular activity in the skin, Zeichner says. The result is revved-up collagen and elastin production, which in turn thickens the skin’s foundation and combats crepiness, wrinkles, and fine lines. Supporting an early lab study published in June 2019 in the International Journal of Cosmetic Science, Zeichner adds that rhamnose may also protect against the hardening of collagen fibers, which happens with age. He says Vichy’s LiftActiv is an example of one skin-care line tapping into the potential superpowers of this ingredient. 

ROSMARINUS OFFICINALIS An extract from rosemary, says the botanical offers antioxidant and antimicrobial properties.

SALICYLIC ACID SA, derived from willow bark, helps slough off dead skin cells that may clog pores, which is why it’s often found in anti-acne products. In addition, SA can be found in stronger versions that “soften and loosen” dry, built-up skin that contributes to calluses and corns on feet, according to MedlinePlus.

SILICA A mineral that’s a component of sand, silica is added to make mixtures thick and to make them absorbent, notes Paula’s Choice.

SODIUM BENZOATE Used as a preservative and in fragrance formulations, says the EWG. Also known as benzoic acid.

SODIUM LAURYL SULFATE A foaming and emulsifying ingredient commonly found in soaps and cleansers. Aside from a risk of irritation, sulfates rank low on the hazard scale, according to the Environmental Working Group’s Skin Deep Cosmetics Database.

SQUALENE According to, squalene is found in the oils naturally present in your skin; it's added to products (this time, derived from plants) to fortify the skin's barrier, which keeps moisture in and locks potential irritants out.

SULFUR A chemical element, notes, sulfur addresses acne (from red, angry zits to black and whiteheads) by targeting pimple-producing bacteria, exfoliating skin cells that plug pores, and controlling oil, according to Proactiv.

TITANIUM DIOXIDE Commonly found in mineral sunscreens, titanium dioxide works to “reflect, scatter, and absorb UVA and UVB rays,” according to the EPA.

WATER You will find water as a main ingredient in most skin-care products, says It’s a solvent for active ingredients and, when mixed with oil, provides the silky texture of skin creams.

ZINC OXIDE Like titanium dioxide, this is another sunscreen ingredient that physically blocks UV light, says the EPA. Mineral sunscreen ingredients are usually gentler on skin, so they’re well suited for sensitive complexions and are often found in sunscreens formulated for babies.