Vita-C Glycolic Serum

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 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.

The smallest and most penetrating alpha hydroxy acid, used to loosen the bonds between dead skin cells for smoother texture and tone. It is a genuine irritant at higher concentrations or low pH, can increase sun sensitivity, and the EU restricts free acid content and requires sunscreen-use wording on labeling.

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

A strong alkali used in tiny amounts to adjust the pH of cosmetics to safe, skin-friendly levels. At the pH found in finished products, sodium hydroxide is neutralized and well tolerated.

A larger, gentler alpha hydroxy acid than glycolic acid, used to exfoliate and to draw in moisture. It can still cause stinging or increased sun sensitivity at higher concentrations, so daytime SPF use is sensible, but it is generally better tolerated than glycolic acid.

The most well-studied form of topical vitamin C, used as an antioxidant and to support collagen signaling and brighten uneven tone. It is acidic and can sting or irritate sensitive skin, and it oxidizes readily once a bottle is opened, which can reduce its effectiveness rather than create a safety issue.

A natural component of skin's own moisturizing system, used at low percentages as a humectant and at higher percentages (10 percent plus) as a mild keratolytic for very dry or rough skin. It can sting broken or eczema-prone skin, especially at higher concentrations.

A disaccharide sugar that acts as a humectant, drawing moisture into the skin and helping prevent dryness. It is well tolerated and commonly found in skincare formulas designed to support skin barrier health.

A naturally occurring compound found in many plants that acts as a humectant to draw water into the skin and also provides antioxidant support. It is well tolerated and used at modest levels in skincare formulations.

A humectant naturally derived from sugar beets that helps skin draw in and hold water; it has a long history of safe use with no meaningful irritation or sensitization concerns.

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.

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

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 silicone polymer used in hair and skin care products for conditioning and shine. It is inert and well tolerated, with no identified safety concerns at cosmetic concentrations.

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.

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 rheology modifier that thickens gels and serums while maintaining a lightweight, non-sticky feel. Provides suspension and stability in water-based formulas. Widely used and well tolerated.

This small glycol is used to thin out formulas and help preservatives work better, similar in role to propylene glycol and butylene glycol already in wide use. Industry and EU safety reviewers have set purity and concentration conditions for its use rather than restricting it outright, and no consumer-relevant hazard has been established at typical cosmetic levels.

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.

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.

Another sugar-and-fatty-alcohol derived non-ionic surfactant, structurally close to coco-glucoside but made from a shorter (decyl, C10) fatty chain. It is a gentle cleanser generally well tolerated, though a small number of contact-allergy case reports exist, mostly in people with pre-existing skin conditions.

A corn-derived solvent and humectant that has largely replaced propylene glycol in "clean" formulas; CIR reviewed the alkane diol group and found use concentrations up to about 40 percent in leave-on products like deodorant sticks with no meaningful irritation signal.

A glycol used very widely in Korean and Western skincare as a lightweight humectant, solvent, and gentle preservative-booster, often in place of traditional preservatives. It has a low reported irritation rate at use levels and is graded low concern in published assessments.

A mineral pigment used to add opacity and soft-focus effects in cosmetics. FDA-approved for cosmetic use and graded low concern in published safety assessments.

Used in tiny amounts to set a product to skin-friendly pH. No concern at those levels.

Caprylyl glycol is a plant-derived humectant that also has mild antimicrobial properties, so it is commonly paired with other preservatives to allow lower overall preservative levels. Available data do not point to meaningful irritation or sensitization concerns at typical use levels.

A widely used preservative, safe at the legal limit of 1% or less. Often the "paraben-free" replacement.

The sodium salt of benzoic acid, used as a preservative in both foods and cosmetics. Decades of safety review support its use at typical cosmetic concentrations, with mild irritation the main reported issue in sensitive skin.

A widely used, gentle preservative also common in food. It is generally well tolerated, though it can occasionally cause mild, transient irritation in people with already-compromised or very reactive skin.

A naturally occurring mineral silicate that adds shimmer and light-diffusing properties to cosmetics. Cosmetic-grade mica is well tolerated and should be free of asbestos and talc contamination.

A mineral UV filter and white pigment used in sunscreens and makeup. It sits on the skin surface rather than being absorbed, and major regulators consider it safe for topical cosmetic use.