Keratin Smooth Conditioner

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

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

A cationic conditioning agent used in rinse-off products like shampoos and conditioners to provide softness and detangling. Generally well tolerated but can cause irritation at high concentrations in some individuals.

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.

A quaternary ammonium conditioning agent that coats hair with a positive charge to smooth the cuticle, cut static, and ease detangling; it is one of the most common conditioning ingredients in rinse-off conditioners. CIR reviewed it as part of the trimonium family and found it safe as used, including in leave-on formulas at typical concentrations.

A silicone-based polymer with amino groups that deposits on hair to provide conditioning and smoothing benefits. It is extensively used in hair care products with a long track record of safe use in rinse-off formulations.

A quaternary ammonium salt used as a conditioning and antistatic agent in hair products. It has been extensively documented as safe in cosmetics when used in typical rinse-off formulations.

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.

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.

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 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.

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 preservative that works by slowly releasing small amounts of formaldehyde to control microbial growth. This makes it an effective preservative, but people with a known formaldehyde or fragrance-type sensitivity may develop irritation or an allergic reaction, especially with prolonged use of leave-on products.

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

Methylchloroisothiazolinone is typically used together with methylisothiazolinone in a 3:1 mix and is a well-documented skin sensitizer at higher rates than most preservatives. EU rules now restrict this combination to rinse-off products only, at a low maximum concentration.

A preservative that caused a wave of contact allergy in the 2010s. The EU banned it from leave-on products and tightly limits it in rinse-off ones. A genuine concern, not a myth.

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 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 jasmine-like fragrance compound frequently used in soaps and lotions. It is one of the 26 EU-designated fragrance allergens, though studies suggest its sensitization potency is comparatively low relative to other listed allergens.

A citrus-scented fragrance component. Fine for most, but it oxidizes over time into a known contact allergen, so it must be labelled in the EU.

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