Reading the label on a skin care product can be overwhelming. There may be a long list of items you aren’t even sure how to pronounce. It’s even harder to know what they do.
Ever wanted a dictionary to help translate skin care labels? Look no further.
This skimmable glossary covers common — and not-so-common — skin care ingredient staples so you can feel confident knowing what you’re putting on your skin.
Is it evidence-based?
Along with definitions, we’ve also included a quick guide to let you know whether each ingredient is evidence-based. We consulted Healthline’s medical review team so you can choose scientifically sound ingredients.
Some are a clear yes, some only have evidence supporting topical or oral use, and others may have mixed, emerging, or limited evidence. Still, others may have historical or cultural uses that have stood the test of time.
Alpha hydroxy acid (AHAs)
Evidence-based: Yes
Alpha-hydroxy acids (AHAs) are water-based plant- and animal-derived ingredients used to smooth wrinkles, improve skin texture, and cleanse. They exfoliate the surface of the skin but may increase sun sensitivity or cause rashes, burning, swelling, peeling, and itching. Learn more.
Amino acids
Evidence-based: Evidence is limited
Amino acids are building blocks of protein that occur naturally in the skin and foods. They’re often used in skin care products as peptides, or short amino acid chains that serve as protein building blocks. They may help keep skin looking firm and reduce breakouts, but scientific evidence is limited. Learn more.
Allantoin
Evidence-based: Evidence is emerging
Allantoin, or aluminum dihydroxy allantoinate, is a chemical compound found in the human body, plants, and animals. It’s most commonly put in moisturizers, though
Aloe vera
Evidence-based: Yes (topical), no (oral)
Aloe vera is commonly used to topically treat acne and sunburn. It also may offer some moisturizing benefits. There is some evidence to support aloe vera use for herpes simplex, lichen planus, and psoriasis treatment, but more quality research is needed. Learn more.
Antioxidants
Evidence-based: Evidence is mixed
Antioxidants, such as Vitamins C and E, may offer benefits such as reversing and reducing damage caused by environmental factors like sunburn and tobacco exposure. Depending on the antioxidant and use, more research is needed to support the topical use of antioxidants. Learn more.
Apple cider vinegar
Evidence-based: No
Apple cider vinegar (ACV) is a health-food ingredient that also appears in DIY skin care recipes. It’s known for killing bacteria, so it’s said to have cleansing and anti-acne benefits, but the evidence is limited. Learn more.
Argan oil
Evidence-based: Evidence is emerging
Argan oil is derived from argan trees native to Morocco. Rich in fatty acids and Vitamin E, it’s found in moisturizers and wrinkle creams. It may reduce inflammation, but research is still emerging. Learn more.
Avocado oil
Evidence-based: Evidence is limited
Benefits of topical use of avocado oil may include quicker wound healing, plaque psoriasis treatment, and moisturizing. However, most studies on the topical use of avocado oil involve using it in conjunction with another ingredient, so more research is needed. Learn more.
Azelaic acid
Evidence-based: Yes
Found naturally in grains like wheat and barley, azelaic acid boasts anti-inflammatory properties that make it effective for treating skin conditions such as acne, though research suggests it’s less effective than benzoyl peroxide. Learn more.
Astaxanthin
Evidence-Based: No
Astaxanthin is a synthetically-made antioxidant used for cosmetic purposes such as moisturizing. More large clinical studies are needed to prove its effectiveness. Learn more.
Baking soda
Evidence-based: No
Baking soda, or sodium bicarbonate, is a basic chemical that helps neutralize acid. It’s sometimes used in DIY acne and skin treatments, but there’s a risk of overdrying. It can strip the skin of its barrier and natural oil, leaving it more susceptible to bacteria and future breakouts. Learn more.
Beta hydroxy acids (BHAs)
Evidence-based: Yes
Beta hydroxy acids (BHAs) may reduce wrinkles, sun damage, and acne and improve the texture of the skin through exfoliation. They’re typically less harsh than alpha hydroxy acids (AHAs,) and salicylic acid is a commonly used BHA in acne treatments. Learn more.
Bakuchiol
Evidence-based: Evidence is limited
Bakuchiol is a plant extract and antioxidant thought to support healthy aging that may have been used in traditional Chinese and Indian medicine. It’s sometimes promoted as a safer, less irritating alternative to retinol, but there currently aren’t enough studies to support these claims. Learn more.
Beeswax
Evidence-based: Evidence is limited
Beeswax is a wax produced by worker bees to build a honeycomb. It’s often found in makeup products and some sunscreens and may help manage sensitive skin, dermatitis, and psoriasis. It’s sometimes used as an emollient to support skin hydration. Research is still limited. Learn more.
Benzoyl peroxide
Evidence-based: Yes
Benzoyl peroxide is a common ingredient in over-the-counter gels, cleansers, and spot treatments in varying concentrations. It’s known to kill acne-causing bacteria on the skin and in the hair follicles. It’s considered a category C substance, meaning there’s some safety risk involved, and it may cause dryness or irritation. Learn more
Benzenes
Evidence-based: No
The FDA considers Benzene a solvent used in the manufacturing of some plastics and detergents. The FDA considers benzene a Class 1 solvent because of its toxicity and negative environmental impact. It’s a known carcinogen, primarily for blood cancers like leukemia. Learn more.
Bithionol
Evidence-based: No
Bithionol is an antibacterial ingredient found in some detergents, creams, and lotions. It’s prohibited by the FDA because it may cause photo contact sensitization, or irritation when exposed to the sun. Learn more.
Biotin
Evidence-based: No
Biotin, or vitamin H, is part of a class of complex B vitamins that help the body convert food to energy. Biotin deficiencies are rare but may trigger hair loss or skin rashes. Evidence of using the ingredient topically to solve these issues doesn’t exist, nor does data support the idea that taking it orally helps with nail, hair, and skin health. Learn more.
Broad-spectrum sunscreen
Evidence-based: Yes
Broad-spectrum sunscreens protect against UVA & UVB rays by creating a chemical barrier on the skin to absorb or reflect UV radiation. Research suggests it’s an important step in reducing sun damage risks, such as aging and skin cancer. Learn more.
Butylene glycol
Evidence-based: Mixed
Butylene glycol is a type of alcohol found in shampoos, serums, and acne products. It may have moisturizing and anti-acne benefits, but research is limited, and some reports say it may worsen breakouts. Learn more.
Caffeine
Evidence-based: Evidence is limited
Caffeine like that found in coffee and tea is used in skin care products to reduce the appearance of things like cellulite, acne, sunspots, and dark circles by dilating blood vessels. However, research is limited. Learn more.
Calcium bentonite clay
Evidence-based: Evidence is limited
This absorbent clay typically forms from aged volcanic ash. It’s been used for centuries as a way to detoxify the body, improve digestion, improve skin tone, and more. Research suggests it may increase the efficacy of sunscreen, but the evidence is limited. Learn more.
Castor oil
Evidence-based: Evidence is limited
Castor oil, a thick multipurpose vegetable oil, may serve as a humectant in skin care products by locking in moisture. Learn more.
CBD oil (Cannabidiol)
Evidence-based: Evidence is emerging
Cannabidiol, or CBD, is derived from cannabis but does not contain tetrahydrocannabinol (THC), which triggers the high associated with cannabis. It may help with free radical damage and inflammation, but research on safety and efficacy is emerging. Learn more.
Calamine lotion
Evidence-based: Evidence is emerging
This pink lotion may soothe mild itchiness stemming from issues like poison ivy, shingles, and minor burns. It does not cure these issues, though. Learn more.
Carrier oil
Evidence-based: Evidence is emerging
Carrier oil is a term that encompasses several plant-derived oils, like jojoba oil and argan oil. They get their name because they are good for diluting other products, like essential oils, and “carrying” them to the skin. Evidence of benefits, such as skin longevity and anti-inflammatory properties, is emerging. Learn more.
Ceramides
Evidence-based: Yes
These fatty acids, also known as lipids, make up about half of the epidermis or the outer-most layer of the skin. They may help moisturize the skin and protect it from environmental damage. Learn more.
Citric acid
Evidence-based: Evidence is limited
This lesser-known AHA is used as an exfoliator to help with skin turnover. Learn more.
Chamomile
Evidence-based: Evidence is limited
Chamomile comes from the flower and may come in several forms, including oils or lotions. It may have anti-inflammatory and anti-acne properties and soothe redness and irritation. Learn more.
Charcoal
Evidence-based: No
Activated charcoal is found in facial cleansers, soaps, and scrubs. It’s thought to cleanse the skin, improve complexion, and fight acne, but most evidence is anecdotal. Learn more.
Chia seed oil
Evidence-based: Evidence is emerging
Chia seed oil is derived from the plant Salvia hispanica L and is packed with antioxidants, minerals, and fatty acids. Research on topical use for benefits like skin longevity and dry skin relief is emerging. Learn more.
Chlorofluorocarbon propellants (CFCs)
Evidence-based: No
The FDA prohibits the use of chlorofluorocarbon (CFC) propellants in cosmetic aerosol products, like hairspray and sunscreen. Research suggests they heighten the risk of cancers, including skin cancer. Learn more.
Coconut oil
Evidence-based: Evidence is limited
Coconut oil is a type of plant-derived fat. Topical use on the skin may
Cold-pressed
Evidence-based: No
Cold-pressing involves making a product or ingredient without the use of high heat. The process may help relieve dry skin and scalp and dry or cracked cuticles, but research is limited. Learn more.
Collagen
Evidence-based: Yes
Collagen is the most common protein in the human body but decreases over time. Collagen loss eventually shows on the face in the form of fine lines and wrinkles. Using oral and topical products with collagen can help replace the amount lost. Any product that claims to remove wrinkles or increase collagen production must be FDA-approved. Learn more.
Dimethicone
Evidence-based: Yes
Dimethicone is a human-made silicon-based polymer designed to keep other product ingredients from separating. It may help seal moisture into the skin and hair and prevent aging signs. A 2019 Cosmetic Ingredient Review Expert Panel found products contained less than 15% of dimethicone and that it is safe. Learn more.
Emollients
Evidence-based: Yes
Emollients can be found in creams, ointments, and lotions. They can soften and soothe dry, rough, and flakey skin. Learn more.
Epidermal growth factors (EGF)
Evidence-based: Evidence is emerging
Keratinocytes, fibroblasts, and melanocytes are examples of epidermal growth factors (EGF), which are vital for wound healing. Research on the purported benefits of EGF and how they may delay the degeneration of skin is limited and emerging. Learn more.
Eucalyptus oil
Evidence-based: No
Eucalyptus oil is an essential oil made from dried, crushed, and distilled eucalyptus leaves. It may help improve wound healing and fight inflammation, but peer-reviewed evidence is limited. Learn more.
Ferulic acid
Evidence-based: No
This plant-based antioxidant is often found in products that support skin longevity. Some older research suggests it may help with photoaging and skin cancer, but more research is needed. Learn more.
Formaldehyde
Evidence-based: No
Formaldehyde is used as a preservative but is considered a potentially dangerous carcinogen. It’s found in keratin hair smoothing treatments also noted for its risk of allergic reaction and irritation of the eyes and respiratory tracts. Learn more.
Glycerin (glycerol)
Evidence-based: Yes
There is sufficient evidence to support the use of glycerin (also called glycerol) in skin care products. It may boost hydration, relieve dry skin, and help wounds heal more quickly. Learn more.
Glycolic acid
Evidence-based: Yes
This acid fights acne by breaking bonds between the outer skin cell layers and the next layer of skin cells, triggering a peeling effect. It’s considered pregnancy-safe. Learn more.
Grapeseed extract
Evidence-based: Evidence is emerging
Grapeseed extract (GSE) is created when antioxidant-rich grape seeds are removed, dried, and pulverized. It may help with wound healing and collagen synthesis, but most of the research has looked at its effects on animals. Learn more.
Goat milk
Evidence-based: Evidence is limited
A trending ingredient in soaps, goat’s milk has lactic acid and fatty acids that may help gently moisturize skin. Research is limited. Learn more.
Green tea
Evidence-based: Yes
Green Tea Phenols (GTP) have anti-inflammatory properties and can act as antioxidants. GTPs have been known to be effective in rosacea and acne treatment. Learn more.
Halogenated salicylanilides
Evidence-based: No
The FDA prohibits the use of halogenated salicylanilides because they can lead to serious skin disorders. dichloromethane, trichloromethane, metabromsalan, and tetrachlorosalicylanilide are halogenated salicylanilides. Learn more.
Hemp oil
Evidence-based: Evidence is emerging
Not to be confused with CBD oil, this ingredient comes from hemp seeds and does not contain THC. It may help with atopic dermatitis treatment and skin inflammation. Learn more.
Hexachlorophene
Evidence-based: No
The FDA restricts the use of hexachlorophene because it can penetrate the skin and have toxic effects. It’s only permitted when no other preservative is effective, but it cannot exceed 0.1% or be used in cosmetics applied to a mucous membrane like the lips.
Hyaluronic acid
Evidence-based: Yes
Hyaluronic acid is commonly found in skin care products because of its moisturizing and skin longevity benefits. It’s hydrating and helps keep active ingredients within the moisturized layers of the skin. Learn more.
Hydrocortisone
Evidence-based: Yes
Hydrocortisone can be taken as a tablet or an injectable. It’s used to aid in treating skin disorders like severe psoriasis and allergies. It’s not available over the counter and is in a class of drugs known as glucocorticoids or adrenocorticoids, so it should be taken under the care of a doctor. Learn more.
Hydrogen peroxide
Evidence-based: No
Once considered an effective acne treatment and way to lighten the skin, it’s not advised not to use hydrogen peroxide on the skin. It can cause damage that can actually worsen acne and wound healing. Learn more.
Hydroquinone
Evidence-based: No
Hydroquinone is a skin-lightening agent that reduces hyperpigmentation by lowering the amount of melanin-making melanocytes. It’s not available over the counter because it’s listed as a category C substance. However, no significant risk has been found with topical use. Learn more.
Humectants
Evidence-based: Yes
Humectants attract water, helping the skin retain moisture and stay hydrated. Some humectants directly supply moisture to the skin, while others exfoliate first. Learn more.
Jojoba oil
Evidence-based: Evidence is emerging
Jojoba oil (actually a liquid wax) comes from the jojoba plant, which grows in North America. More research is needed on its benefits for moisturizing, wound-healing time, and cleansing. Learn more.
Kaolin clay
Evidence-based: Evidence is limited
Kaolin clay, sometimes referred to as China clay and white clay, has been used in China to produce porcelain products for hundreds of years. More research on the effectiveness of kaolin clay’s anti-inflammatory and anti-bacterial benefits is needed. Learn more.
Keratin
Evidence-based: No
Mostly used in hair products, keratin is a fibrous protein that also occurs naturally in hair, skin, and nails. Salon keratin treatments contain formaldehyde, and prolonged exposure can have side effects. These treatments are not recommended for pregnant people. Learn more.
Kojic acid
Evidence-based: Evidence is emerging
Kojic acid comes from several types of fungi and is a byproduct of fermented foods like Japanese sake. It’s approved for cosmetic products at 1% or less and is most commonly used for skin-lightening to help with hyperpigmentation or dark spots. Learn more.
Lactic acid
Evidence-based: Yes
Lactic acid is a water-soluble AHA that appears in skin care products for exfoliation and hydration. Learn more.
Lactobionic acid
Evidence-based: Yes
Lactobionic acid is part of a class of Polyhydroxy acids (PHAs) that can exfoliate the skin with less irritation than other chemical exfoliants. Learn more.
Lanolin oil
Evidence-based: Yes
Sheep secrete this oil through their skin, and it’s similar to human sebum. It’s found in nipple creams, lotions, and balms for its moisturizing benefits, but individuals with wool allergies should patch-test any products containing lanolin oil first. Learn more.
Lavender oil
Evidence-based: Evidence is emerging
Lavender essential oil comes from the flowers of the lavender plant and is found in skin care products. It may help reduce acne, wrinkles, dry skin, and hyperpigmentation, but research is limited. Learn more.
Lemon
Evidence-based: No
Lemon is full of vitamin C and may have benefits as an occasional spot treatment. However, applying it to the face may have side effects like redness, irritation, and an increased sunburn risk. Learn more.
Lysine
Evidence-based: Mixed
Lysine is an essential amino acid and protein-building block. Evidence of lysine’s ability to protect against or help heal cold sores is inconsistent. It may quicken wound-healing duration. Learn more.
Magnesium oil
Evidence-based: No
Magnesium oil comes from a mix of magnesium chloride flakes and water. Research on the benefits of topical use of magnesium oil is limited. Learn more.
Malic acid
Evidence-based: Yes
Malic acid naturally occurs when the human body converts carbohydrates into energy and is also found in wine and produce. It’s an AHA that adjusts acid levels in products and for hydration and gentle exfoliation. Learn more.
Mandelic acid
Evidence-based: Yes
Mandelic acid is an alpha hydroxy acid (AHA) that may help improve acne, hyperpigmentation, and skin texture with consistent use. Learn more.
Mercury compounds
Evidence-based: No
The FDA restricts the use of mercury compounds, which are easily absorbed into the skin and accumulate in the body. They may cause allergic reactions, skin irritation, and neurotoxicity, so they may only be used in eye-area products at concentrations of no more than 0.0065% if a safe and effective alternative preservative isn’t available. Learn more.
Methylene chloride
Evidence-based: No
The FDA prohibits the use of methylene chloride, an aerosol typically found in paint strippers that are sometimes found in cosmetics products. It causes cancer in animals and is likely harmful to humans. Learn more.
Milk
Evidence-based: No
Dairy milk contains lactic acid, an alpha hydroxy acid (AHA) that helps stimulate cell growth. However, the topical use of cow’s milk for skin care purposes, such as acne treatment or cleansing, is not proven effective. Learn more.
Milk thistle
Evidence-based: Evidence is emerging
Milk thistle is an herbal, oral supplement derived from Silybum marianum, or milk thistle plants. One study suggested a milk thistle supplement could reduce acne, but more robust research is needed. Learn more.
Mineral oil
Evidence-based: Evidence is limited
Mineral oil comes from petroleum and may help lubricate the skin and retain moisture. It’s often suggested for home skin care remedies, but peer-reviewed research is limited. Learn more.
Niacinamide
Evidence-based: Yes
Niacinamide is a form of Vitamin B3 that doesn’t occur naturally in the body. It can be added through topical products or food like fish. It’s used to support healthy aging, hyperpigmentation, fine lines, wrinkles, and acne treatment and is considered pregnancy-safe. Learn more.
Occlusive
Evidence-based: Yes
Occlusives, like petroleum jelly, hold in water by acting as a barrier. They’re usually oil-based. Learn more.
Olive oil
Evidence-based: Mixed
Typically used in food preparation, topical use of olive oil in soaps may help treat acne. However, olive oil may also worsen issues such as skin sensitivity and acne. Learn more.
Omega-fatty acids
Evidence-based: Evidence is emerging
Found in foods like walnuts and salmon, omega-fatty acids are polyunsaturated fatty acids also available in supplement form. They may protect against sun damage, decrease acne lesions, and moisturize the skin. Learn more.
Panthenol
Evidence-based: Evidence is emerging
Panthenol is a chemical made from panthenolic acid, or Vitamin B5. It becomes vitamin B5 when the body absorbs it and may appear on labels as dexpanthenol, D-pantothenyl alcohol, butanamide, alcohol analog of pantothenic acid, or provitamin B5. It may help with red skin and irritation and is generally considered safe at levels of 5% in topical products. Learn more.
Parabens
Evidence-based: No
Parabens, such as Isobutyl, Isopropyl, Propyl, Methyl, and Butyl, are used as preservatives. They may cause endocrine disruption resulting in harm to reproductive systems. Learn more.
Peppermint oil
Evidence-based: Evidence is emerging
Peppermint oil is the essential oil of peppermint plants that grow naturally in Europe and North America. Peppermint oil may help cool and soothe skin, increase blood flow, and protect against bacteria and yeast. However, evidence is limited. Learn more.
Petroleum jelly
Evidence-based: Yes
Petroleum jelly is a mixture of mineral oils and waxes derived from petroleum. It can act as a physical barrier to help lock in the skin’s natural moisture. This barrier aids in wound healing and dry skin treatment. Learn more.
Prebiotics
Evidence-based: Evidence is emerging
Prebiotics are found in foods and may promote the growth of beneficial bacteria in the gut microbiome. The skin microbiome is composed of different types of bacteria, fungi, viruses, micro-eukaryotes, archaea, and phages. Currently, there’s not enough evidence to recommend for or against the use of probiotics in skin care.
Probiotics
Evidence-based: Evidence is emerging
Probiotics are living microorganisms that may help restore gut bacteria. The skin microbiome is composed of different types of bacteria, fungi, viruses, micro-eukaryotes, archaea, and phages. Currently, there’s not enough evidence to recommend for or against the use of probiotics in skin care. Learn more.
Peptides
Evidence-based: No
Polypeptides, often referred to as peptides, are short chains of amino acids that make up proteins. Some peptides naturally occur in the skin, such as collagen, keratin, and elastin. A loss of peptides can cause softer, wrinkled-looking skin but research on the effectiveness of use in skin care products is limited. Learn more.
Placenta
Evidence-based: Evidence is emerging
The placenta is a temporary organ that develops in pregnant mammals to nourish and deliver oxygen to the developing fetus. It’s nutrient and antioxidant-dense, but evidence of its effectiveness in skin care products is limited. Learn more.
Polyhydroxy acids (PHAs)
Evidence-based: Yes
Polyhydroxy acids (PHAs) are a newer type of Alpha Hydroxy Acids (AHAs) used in skin care products to smooth wrinkles, bolster skin texture, and cleanse. They exfoliate the surface of the skin and help it retain moisture. Learn more.
Pomegranate oil
Evidence-based: Evidence is emerging
Pomegranate oil is derived from the skin of the antioxidant-rich fruit and is often found in serums. It’s high in Vitamin C and may contain natural antimicrobials. Data on its effects is limited. Learn more.
Retinol
Evidence-based: Yes
Retinol is a derivative of Vitamin A used to treat acne and support healthy aging. Retinols are usually available over the counter. They may increase sun sensitivity and are not recommended during pregnancy. Learn more.
Retinoids
Evidence-based: Yes
Retinoids are a derivative of Vitamin A similar to retinol. They’re used to treat acne and support healthy aging but usually require a prescription. They may increase sun sensitivity and are not recommended during pregnancy. Learn more.
Resveratrol
Evidence-based: Evidence is emerging
Resveratrol is an antioxidant found in food and beverages, including wine and grapes. Research on topical use is limited, and the FDA doesn’t regulate supplements, but resveratrol may help with aging, inflammation, and dryness. Learn more.
Rice flour
Evidence-based: No
Rice flour is made by grinding rice grains into powder form. It’s traditionally been used in skin and hair products in Asia, often used to brighten skin. Benefits like exfoliation and UV protection are not currently backed by research. Learn more.
Salicylic acid
Evidence-based: Yes
Salicylic acid is the most common BHA. It acts as an exfoliant and keeps pores clear of breakout-triggering bacteria. It can reduce the appearance of acne and is considered safe to use during pregnancy. Learn more.
Sea salt
Evidence-based: No
Sea salt forms when salt water is evaporated. It’s often found in scrubs and bath mixes. It may help to relieve dryness and inflammation, but claims are not currently backed by data. Learn more.
Shea butter
Evidence-based: Evidence is emerging
Shea butter is extracted from the nuts of a shea tree, typically in West Africa. It’s thick and used in products to soothe and soften the skin, though research is limited. Learn more.
Sodium hydroxide
Evidence-based: No
Many skin care products contain this ingredient, which balances and maintains the pH of a product. It’s safe in small concentrations. Learn more.
Sodium lauryl sulfate
Evidence-based: Yes
Sodium lauryl sulfate (SLS) is a surfactant that reduces the surface tension in ingredients. It serves as a cleaning and foaming agent, and the most recent assessment by the International Journal of Toxicology in 1982 deemed it unharmful for use in products like soaps that are quickly rinsed from the skin. If a product stays on the skin longer, it’s safe to put in products at a maximum concentration of 1%. Learn more.
SPF (Sun protection factor)
Evidence-based: Yes
SPF is the amount of time it would take to get a sunburn if you had not applied sunscreen. It’s the ability of the sunscreen to protect against the UVB rays that cause sunburns but not the UVA rays that cause other skin damage like premature aging. Learn more.
Squalane/squalene
Evidence-based: Yes
Squalane is a hydrocarbon that comes from hydrogenated squalene. This occlusive moisturizer creates a barrier to stop water from evaporating from the skin. While some squalane is animal-derived, there are products available that use plant-derived squalane. Learn more.
Sulfur
Evidence-based: Yes
Sulfur is a mineral frequently found in over-the-counter and prescription acne treatments because it absorbs excess oil, dries out the skin surface, and helps unclog pores. It tends to be gentler than other common ingredients in acne treatment, like benzoyl peroxide and salicylic acid. Learn more.
Tea tree oil
Evidence-based: Yes
Tea tree oil is an essential oil that comes from the Melaleuca alternifolia tree. It has antimicrobial properties that may effectively help treat acne and inflammation. Learn more.
Titanium dioxide
Evidence-based: Yes
This ingredient is often found in chemical sunscreen and makeup with SPF. It’s a broad-spectrum UV filter, and the FDA has deemed it safe for children older than 6 months. Learn more.
Tranexamic acid
Evidence-based: No
Tranexamic acid is most often used in skin care for melasma, a skin condition that causes dark, discolored patches. Topical, intradermal, and oral tranexamic acid have all been used to attempt to treat the condition, but data on efficacy is limited. Learn more.
Turmeric
Evidence-based: Evidence is emerging
A cooking spice, turmeric is also used as a skin care treatment for issues like acne scarring and psoriasis, but no conclusive studies prove these benefits. Learn more.
Vitamin A
Evidence-based: Yes
Vitamin A is fat-soluble vitamin and nutrient that supports skin health. It’s found topically in skin care products like retinoids, which help with acne and maturing skin. Learn more.
Vitamin C
Evidence-based: Yes
Vitamin C is a water-soluble vitamin often found in products like serums to help stabilize and promote collagen production, inhibit melanin synthesis, and lower collagen degradation. Learn more.
Vitamin E
Evidence-based: Evidence is emerging
Vitamin E is a group of fat-soluble compounds found in food, supplements, creams, oils, and serums. It may help reduce UV damage and dryness, but research on the topical application is limited. Learn more.
Vitamin K
Evidence-based: Evidence is emerging
Vitamin K is a fat-soluble vitamin found in topical products that purport to help with dark spots, stretch marks, and scarring. Research is limited. Learn more.
Witch hazel
Evidence-based: Evidence is emerging
Witch hazel, or Hamamelis virginiana, is a flowering plant used in skin care products or by itself to treat conditions like acne, psoriasis, and burns. Learn more.
Vinyl chloride
Evidence-based: No
Vinyl chloride is a flammable, colorless gas. The FDA prohibits this ingredient in aerosol products because it causes health issues like cancer. Learn more.
Zinc oxide
Evidence-based: Yes
Zinc oxide is a mineral commonly found in sunscreen. It can prevent UV rays from penetrating the skin and damaging cells. Learn more.