Advanced Original Essence Repair 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 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.

Pentylene glycol is a humectant and solvent that also offers mild antimicrobial support in formulas. It is generally well tolerated, with only rare reports of irritation, mostly in already sensitive or compromised skin.

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

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 preservative and antioxidant that helps prevent microbial growth and oxidative degradation in formulas. Published assessments support its use at cosmetic levels.

A cross-linked polymer used to thicken formulas and create lightweight gel textures. The large molecular weight prevents penetration into the skin and is not absorbed; well tolerated in cosmetics.

An ester that combines cetyl alcohol with ethylhexanoic acid, serving as an emollient. It softens skin and is well tolerated in cosmetics.

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 soothing, skin-conditioning compound (also found in comfrey root) commonly added to calm and hydrate irritated or sensitive skin. It has a long history of safe use with very low irritation potential.

A key structural lipid naturally found in healthy skin that reinforces the barrier and improves hydration. It is well established in skincare formulations and assessed as having excellent safety across all skin types, including sensitive and compromised barriers.

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 signal peptide designed to modulate muscle contraction and reduce the appearance of expression lines without systemic effects. Cosmetic formulations are well tolerated, with published assessments confirming safety at recommended concentrations.

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.

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.

An emulsifier made from glycerin and stearic acid that stabilizes oil-in-water and water-in-oil formulations. It has a long history of safe use in cosmetics and is assessed as a low-concern ingredient in published safety reviews.

A starch derivative used in cosmetics to thicken formulations and improve texture. It has been used safely in food and cosmetics for decades and shows low irritation potential across rinse-off and leave-on products.

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.

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 blend of cetyl and stearyl fatty alcohols used to thicken lotions and soften skin. It is chemically unrelated to drying alcohols like ethanol, and the CIR expert panel has found fatty alcohols safe as used in cosmetics.

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 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 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.

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

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.

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 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.