Retinol 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.

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 lightweight, silicone-like emollient derived from coconut/palm fatty alcohols, used to give lotions a smoother, less greasy feel. Listed in the EU CosIng database as a skin-conditioning agent with no restrictions.

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

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.

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 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.

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.

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

A synthetic surfactant widely used to emulsify oils and water in cosmetics. It is well tolerated and has been used safely in cosmetic formulations for decades.

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 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 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 next-generation retinoid ester designed to be more stable and gentler than retinol. Early published research suggests it is well tolerated and may support skin renewal with less irritation potential than earlier retinoids, though long-term studies continue.

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

A widely used emulsifier and solubilizer that has been in cosmetics and pharmaceuticals for decades. The CIR has assessed it as safe with no known concerns at typical cosmetic concentrations. As with any surfactant, some people with very sensitive skin may experience mild irritation.

A peptide lipid that mimics collagen fragments and signals skin cells to increase collagen production while reducing inflammation. Established in anti-aging formulas with a consistent safety record.

A signal peptide attached to palmitic acid that activates collagen synthesis in skin cells. Well tolerated across skin types with no significant safety concerns in cosmetic use.

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