Gongjinhyang Soo Vital Hydrating Essence

The base most products are built on. It carries the other ingredients and has no safety concern.

A humectant that draws water into the skin. One of the best-studied, best-tolerated ingredients in personal care.

A light, low-odor glycol used as a solvent and humectant, extremely common in Korean toners and essences. It has a low reported irritation rate and is graded low concern in published assessments.

A fast-evaporating solvent used to carry actives and give toners a light, "clean" feel; at the concentrations used in classic astringents it can be genuinely drying or irritating with repeated use, especially on dry or compromised skin, though it is not inherently toxic and is a normal, well-studied cosmetic ingredient.

A smooth synthetic emollient ester used to soften skin and carry oil-soluble ingredients. It is well tolerated and graded low concern in published assessments.

A silicone that gives a smooth, soft feel and helps hold water in the skin. Inert and well studied.

A lightweight, volatile silicone that gives serums and primers their silky slip and quick-evaporating finish. Human safety data are reassuring; the EU restriction on this ingredient in rinse-off products is about environmental persistence in waterways, not skin safety.

A phospholipid emulsifier from soy or sunflower that binds water and oil and helps other ingredients absorb. It is a natural component of skin membranes, well tolerated, and reviewed as safe as used; a soy-derived grade is not a meaningful concern for a soy food allergy because the protein is largely absent.

A lightweight humectant and solvent similar in role to propylene glycol, used to carry actives and give lotions a lighter feel. CIR has reviewed it and considers it safe as used in cosmetics.

A soothing humectant that helps skin and hair look conditioned. Very well tolerated.

A fermented soybean extract used in skincare for its hydrating and skin-conditioning properties. Well tolerated in cosmetic formulations without documented safety concerns at cosmetic concentrations.

An energizing plant extract used in skincare preparations, known for antioxidant activity in cosmetic applications. Cosmetic safety assessments generally support its use, though like many botanical ingredients it may trigger reactions in very sensitive individuals.

A traditional East Asian botanical extract used in cosmetics for hydrating and claimed soothing properties. Limited modern cosmetic safety data exists, but it has a long history of topical use and no documented safety concerns have emerged in the available literature.

A synthetic polymer used to create film-forming serums and gels. It is stable, non-irritating, and widely used in cosmetic formulations to improve texture and adherence without toxicological concerns.

A humectant sugar alcohol that draws water into the skin. It is well tolerated and widely used in skincare and food. Not known to cause concern at the concentrations used in cosmetics.

A synthetic emollient with properties similar to silicones, used for a smooth skin feel. Inert and not absorbed through intact skin, with no documented safety concerns in cosmetic formulations.

A lightweight, odorless emollient made by combining coconut or palm-derived fatty acids with glycerin. It spreads easily, feels non-greasy, and has a long history of use in skin and hair products with no meaningful irritation or sensitization signal.

A stable, saturated version of squalene, a lipid the skin already produces, now usually sourced from olives or sugarcane instead of shark liver. It is very well tolerated across skin types and helps reinforce the skin barrier.

A long-chain fatty acid with 22 carbons, used to thicken and stabilize lotions and creams. CIR has reviewed fatty acids and found them safe for cosmetic use. It is similar to stearic acid and is a standard emulsifier in skincare formulations.

A naturally occurring fatty acid (also made in the body and found in many foods) used to thicken lotions and help stabilize cleansing bars. It is one of the most well-studied emollient ingredients and is not a meaningful irritant at cosmetic use levels.

A long-chain fatty alcohol used to thicken and stabilize creams and soften skin. It is a waxy emollient, not a drying solvent, and is graded low concern in published assessments.

A fatty alcohol derived from stearic acid that thickens creams and gives them a smooth, non-greasy glide. It is one of the fatty alcohols the CIR panel reviewed together and found safe as used, with a very low reported rate of contact sensitization.

Carbomer is a synthetic polymer used purely to thicken and stabilize gels and lotions, with negligible skin penetration due to its large molecular size. Safety reviews have found low toxicity and minimal irritation potential even in leave-on use.

A lightweight carrier oil expressed from macadamia nuts, rich in oleic acid and similar in composition to skin lipids. Very well tolerated in cosmetic use, though individuals with tree nut allergies who are cautious may want to patch test.

A sugar-derived emulsifier that bridges oils and water in skincare formulas. It is gentler and plant-sourced, making it popular in natural and gentle formulations. Well tolerated with no known safety concerns.

A rich plant butter pressed from shea tree nuts, valued for softening and cushioning dry skin. It is generally well tolerated, though very rare allergic reactions have been reported and people with tree nut allergies who are cautious may want to patch test first.

Used like sodium hydroxide to adjust pH in cosmetics at very low levels. At finished-product pH, it is neutralized and well tolerated.

A more stable, esterified form of vitamin E used as an antioxidant and skin-conditioning ingredient. It is a different substance from the vitamin E acetate implicated in vaping-related lung injury, which involved inhaling the oil, not applying it topically to skin.

A common emulsifier and texture-softener made from glycerin and stearic acid. CIR review of this class found no evidence of reproductive, carcinogenic, sensitizing, or phototoxic effects in the studies examined.

A PEG-based emulsifier that blends oils and water in formulas. It is a workhorse ingredient in stable emulsions and is approved for cosmetic use. Well tolerated.

Xanthan gum is a microbial-fermentation-derived polysaccharide used to thicken and stabilize textures, similarly common in food. Cosmetic panel review of this and related microbial gums found them safe as used, with no meaningful irritation signal at typical concentrations.

A saturated fatty acid used as an emollient and texture ingredient in creams and formulations. It is well tolerated and commonly used at safe concentrations.

A chelating agent that binds trace metal ions to keep formulas stable and preservatives working properly. It is not a functional skincare "active" and only a very small amount is used, with minimal skin penetration expected.

A polysaccharide produced through fermentation that thickens formulations and provides hydration. It is used across rinse-off and leave-on cosmetics with a low irritation profile, though very rare sensitivities to fermented polysaccharides have been documented.

A mineral thickener and anti-caking agent widely used in sunscreens and cosmetics to control texture and prevent ingredient separation. CIR has reviewed silica in cosmetic use and found no basis for concern at the levels used topically.

A lab-made version of a lipid naturally found in the outer skin barrier. It is added to creams and cleansers to help replace lipids that washing can strip away, and it is not linked to irritation or safety concerns.

A waxy sterol found naturally in skin and used in cosmetics as an emollient and emulsifier. It supports the skin barrier and is well tolerated across skin types.

A synthetic surfactant and emulsifier that blends oils and water in cosmetics and has been used safely for decades in cosmetics and pharmaceuticals. Published safety literature is extensive and reassuring at cosmetic levels.

A buffering agent used in tiny amounts to set a product's pH, most often alongside gel-forming polymers. It is graded low concern in published assessments at the levels used.

A class of naturally derived lipid compounds used to soften skin and support barrier health. They are extracted from plants or microorganisms and used at low concentrations as conditioning agents. Well tolerated with rare contact sensitivity.

An antioxidant that helps protect a formula and condition skin. Well tolerated.

A glycerin derivative used as a skin conditioner and preservative booster, often paired with phenoxyethanol to allow lower total preservative levels. It has a low irritation and sensitization profile in safety reviews.

An undisclosed scent blend that can contain dozens of components. The single most common cause of cosmetic contact allergy, and the blend is not itemized, so you cannot see what is in it.

Alpha-isomethyl ionone is a violet-scented fragrance material and one of the EU-listed allergens requiring label disclosure. Documented sensitization is more common with this ingredient than with many other listed fragrance allergens.

A fragrance fixative and solvent found naturally in balsams and used to help scents last longer. It is one of the 26 EU-designated fragrance allergens, with documented but uncommon contact sensitization.

A natural fragrance component found in citrus oils and lemongrass, giving a lemony scent. It is a named EU fragrance allergen that can oxidize into potent contact allergens over time; people with known fragrance sensitivities may react.

A rose-scented fragrance ingredient found naturally in geranium and rose oil. It is one of the 26 fragrance allergens the EU requires to be labeled by name because a minority of people develop skin sensitization to it, though most users tolerate it without issue.

A floral, rose-like fragrance compound found in many essential oils. It is one of the 26 EU-designated fragrance allergens, meaning a documented minority of people can develop contact sensitization, so brands must disclose it above set thresholds.

Hydroxycitronellal is a lily-of-the-valley scented fragrance ingredient on the EU allergen disclosure list. It has well-documented sensitizing potential in patch-test studies, so it is worth checking the label if you have known fragrance sensitivities.

A citrus-scented fragrance component. Fine for most, but it oxidizes over time into a known contact allergen, so it must be labelled in the EU.

A floral fragrance component and one of the EU-labelled fragrance allergens. Usually fine, worth watching if you react to scented products.