TNS Essential Serum

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

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

A fatty alcohol derived from arachis oil or synthesized, used as an emollient and emulsifier in creams and lotions. It is well tolerated and graded safe for cosmetic use.

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

A rich plant butter pressed from shea tree nuts, valued for softening and cushioning dry skin. It is generally well tolerated, though very rare allergic reactions have been reported and people with tree nut allergies who are cautious may want to patch test first.

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 protein fragment derived from animal keratin that helps hair retain moisture and improves strength and shine. It is well tolerated across hair types and does not carry the allergen risk of plant-derived hydrolyzed proteins.

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

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

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

An ester of palmitic acid and ethylhexanol, commonly used as an emollient and skin-conditioning agent. It is well studied and well tolerated in cosmetics.

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 long-chain fatty alcohol used to thicken and stabilize creams and soften skin. It is a waxy emollient, not a drying solvent, and is graded low concern in published assessments.

A sugar-derived emulsifier that bridges oils and water in skincare formulas. It is gentler and plant-sourced, making it popular in natural and gentle formulations. Well tolerated with no known safety concerns.

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 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.

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

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.

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.

Hydroxycitronellal is a lily-of-the-valley scented fragrance ingredient on the EU allergen disclosure list. It has well-documented sensitizing potential in patch-test studies, so it is worth checking the label if you have known fragrance sensitivities.

A floral fragrance component and one of the EU-labelled fragrance allergens. Usually fine, worth watching if you react to scented products.

A sweet, hay-like fragrance ingredient naturally found in tonka bean and lavender. It is one of the 26 EU-designated fragrance allergens and is also subject to an EU maximum concentration limit in finished cosmetic products.

Alpha-isomethyl ionone is a violet-scented fragrance material and one of the EU-listed allergens requiring label disclosure. Documented sensitization is more common with this ingredient than with many other listed fragrance allergens.

A floral, rose-like fragrance compound found in many essential oils. It is one of the 26 EU-designated fragrance allergens, meaning a documented minority of people can develop contact sensitization, so brands must disclose it above set thresholds.

Isoeugenol is a clove-scented fragrance compound and is considered one of the more potent sensitizers among the EU-listed fragrance allergens. It is disclosed on labels so people with a known allergy can avoid it.