Retinal + Niacinamide Youth Serum

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

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

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

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 retinoid that your skin converts to retinoic acid, used to support cell turnover and collagen production. Published assessments grade it low-concern and well tolerated; retinoids can irritate sensitive or compromised skin, so start low and build tolerance gradually.

A linoleic-acid-rich plant oil used as an emollient and, in some small pediatric studies, associated with support of the skin barrier when applied to infant skin. It is well tolerated with a low reported rate of contact reactions.

A chemically cross-linked form of sodium hyaluronate designed to remain on the skin surface longer and provide sustained hydration. It functions as a humectant and is well tolerated, with the same safety profile as standard hyaluronic acid.

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.

One of the three major ceramides naturally found in human skin. Ceramide AP plays a critical role in maintaining the skin barrier and is extensively studied as a safe, essential ingredient. It is derived synthetically or from plant sources.

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 crosslinked acrylic polymer that thickens and stabilizes formulations. Published assessments show it to be well tolerated at cosmetic use levels, with no evidence of penetration into viable skin layers or systemic absorption.

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

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

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

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 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.