Hydra-hyal Serum

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

A water-soluble humectant that holds moisture and gives essences a soft feel. It is well tolerated and graded low concern in published assessments.

A polyethylene glycol ester of hydrogenated castor oil, widely used as an emulsifier and solvent in rinse-off and leave-on cosmetics. PEG-modified ingredients are graded as safe in cosmetics by the CIR when formulated at typical use levels.

A lower molecular weight version of hyaluronic acid designed for better skin penetration. It has been extensively studied and shown to support skin hydration and barrier function with excellent tolerability in diverse formulations and skin types.

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.

An undisclosed scent blend that can contain dozens of components. The single most common cause of cosmetic contact allergy, and the blend is not itemized, so you cannot see what is in it.

A modified starch polymer used to thicken and film-form in cosmetics. It is readily broken down in the environment and well tolerated in topical use, with no known sensitization concerns at typical cosmetic concentrations.

A plant-derived emollient and emulsifier made from glycerin and oleic acid, typically from olives or canola. Softens skin while stabilizing oil-water formulas; well tolerated at typical use levels.

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

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 seaweed-derived extract used to thicken and hydrate cosmetic formulas. It is well tolerated and has a long history of use in both skincare and food products.

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

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.

A common preservative and fragrance/solvent ingredient found naturally in many essential oils. It is well tolerated by most people at the levels used in cosmetics, but it is one of the 26 EU-designated fragrance allergens and can trigger reactions in people with an existing sensitivity.

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.

A naturally occurring nucleoside used in anti-aging formulas, often marketed for smoothing the look of fine lines. It has a low irritation profile and no established hazard at cosmetic use levels.

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 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 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.

A nutrient-rich oil pressed from sweet almond kernels, used to soften and condition skin. It is generally well tolerated, though people with tree nut allergies should patch test first, as it can rarely trigger allergic reactions.

Ordinary salt, used in surfactant-based products like shampoos and body washes to adjust viscosity by interacting with the surfactant micelles. It has no meaningful toxicity concern at cosmetic use levels; the main practical downside is that too much can make a formula feel less mild.

Dehydroacetic acid is a preservative regulated under the EU preservative annex with a set maximum concentration. Sensitization appears to be rare, though occasional contact dermatitis case reports exist, so people with reactive skin may want to patch test.

A simple sugar that functions as a humectant to bind moisture into the stratum corneum and is a component of the natural moisturizing factor. It is well tolerated in cosmetics and has no known sensitization concerns.

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

A mineral salt used in cosmetics as a humectant and antioxidant. It is the same compound used in food and personal care products, and is well tolerated in both rinse-off and leave-on formulations.

A buffering salt used to maintain stable pH in cosmetic products. It has a well-established safety history in cosmetic use.

The most well-studied form of topical vitamin C, used as an antioxidant and to support collagen signaling and brighten uneven tone. It is acidic and can sting or irritate sensitive skin, and it oxidizes readily once a bottle is opened, which can reduce its effectiveness rather than create a safety issue.

The sodium salt of lactic acid and a key component of the skin barrier and natural moisturizing factor that attracts water to the skin. It is well established as a safe and effective humectant with no known hazards at cosmetic concentrations.

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

An essential amino acid in salt form, used as a humectant to support skin hydration. Lysine is a recognized component of skin proteins and natural moisturizing factor, with established safe use in cosmetic formulations.

A basic amino acid naturally found in skin that draws moisture into the stratum corneum. It is well tolerated in cosmetics at typical concentrations and has been used safely in skincare formulations for decades.

A non-essential amino acid that occurs naturally in skin and is used in cosmetics as a humectant and skin-conditioning agent. It has an established safety record with no reported concerns at typical usage levels.

A branched-chain amino acid used in conditioning formulas to support skin hydration. No safety concern has been identified at typical cosmetic concentrations.

An essential amino acid that is a component of the skin barrier and natural moisturizing factor, used in cosmetics to improve hydration. It is well tolerated and assessed as safe for topical application.

An essential branched-chain amino acid naturally found in skin and used as a humectant to help retain moisture. It is a recognized component of the natural moisturizing factor with a history of safe use in cosmetics at typical concentrations.

An amino acid used in skin-conditioning formulas to support hydration and skin health. No documented safety concern at cosmetic use levels.

The simplest amino acid, naturally present in skin and collagen, commonly used as a humectant to help retain moisture. It has a long history of safe use in cosmetics with no known hazards at typical concentrations.

A synthetic surfactant and emulsifier that blends oils and water in cosmetics and has been used safely for decades in cosmetics and pharmaceuticals. Published safety literature is extensive and reassuring at cosmetic levels.

A naturally occurring amino acid that is a key component of skin barrier lipids and the natural moisturizing factor. It binds water to the skin and is well established as a safe hydrating ingredient with no known sensitization concerns.

Vitamin B12 used in cosmetics for its purported skin-conditioning and nutritional benefits. It is established as safe for topical use with no known hazards or sensitization concerns at concentrations typically used in skincare.

A naturally occurring tripeptide (amino acid compound) that functions as a cellular antioxidant. It is graded low concern in cosmetic assessments, though absorption across intact skin appears limited.

A triterpenoid from Centella asiatica with published research linking it to skin barrier function and calming effects. It appears well tolerated at cosmetic levels.

An amino acid widely used in cosmetics for skin conditioning and moisture retention. It is well-studied and well-tolerated across skin types at cosmetic use levels.

An amino acid abundant in collagen that functions as a humectant to draw moisture into the skin. It is well tolerated in skincare products and assessed as safe for cosmetic use at standard formulation levels.

A B vitamin (B7) included in cosmetics for skin and hair conditioning effects. It is graded with no known concerns in cosmetic assessments and is well tolerated across skin types.

A gentle humectant derived from glucose. It draws water to the skin and is mild enough for sensitive skin types. Widely used in cosmetics without reported safety concerns.

A naturally occurring compound found in many plants that acts as a humectant to draw water into the skin and also provides antioxidant support. It is well tolerated and used at modest levels in skincare formulations.

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