Hydrating Serum

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

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 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.

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 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 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 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 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.

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

An amino acid derived emulsifier made from stearic acid and glutamic acid that is increasingly used in natural and clean formulations. It is mild, biodegradable, and presents no known safety concerns for cosmetic use.

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 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 synthetic polymer used to thicken and stabilize water-based formulas like gels and serums. It provides texture and suspension of particles without interfering with skin feel. Well established in cosmetics.

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.

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.

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.

Sodium phytate is a plant-derived chelating agent used to bind trace metals and stabilize formulas, often as a preservative booster alongside other preservatives. Available safety reviews have not identified meaningful irritation or sensitization concerns at typical use levels.

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.