Acne Serum

A beta hydroxy acid used to smooth texture and clear pores. Safe at cosmetic levels; can be mildly irritating if overused.

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

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

A form of vitamin B3 used to support a more even-looking tone and a comfortable barrier. Well tolerated at cosmetic levels.

Zinc PCA is a zinc salt of a naturally occurring skin humectant, used mainly to help regulate oil and support a balanced skin microbiome in oily or acne-prone formulas. It has a long history of use with no significant reported irritation, though dedicated cosmetic-specific review data is thinner than for more common ingredients.

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.

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

A stable vitamin C derivative used to brighten and provide antioxidant support, more shelf-stable than pure ascorbic acid. It is generally well tolerated, though strong vitamin C forms can sting sensitive skin.

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 synthetic gelling and stabilizing polymer that gives lotions and gels their smooth, cushiony texture. The large molecule stays on the skin surface rather than penetrating, and it is graded low concern in published assessments.

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

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 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 plant extract long used in traditional wound care and now common in "cica" soothing products, valued for calming redness and supporting the skin barrier. It is generally well tolerated, with rare contact allergy reported.

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 plant-derived water or extract used mainly as a soothing humectant filler. Evidence for dramatic skin benefits beyond mild hydration and soothing is limited, but it is well tolerated by most people.

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 humectant that holds water at the skin surface for a more hydrated look. No safety concern.

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

A naturally derived humectant made from fermented plant sugars that draws water into the skin. It is well tolerated in cosmetics and is used to support hydration and skin softness.