Hydrate Shampoo

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

A coconut-derived mild surfactant best known as the main cleansing agent in syndet ("soap-free") bars and gentle body washes. It has a good tolerability record and is often chosen specifically for sensitive or eczema-prone skin.

A mild anionic surfactant formulated as a gentler alternative to traditional sulfates, commonly used in sulfate-free shampoos and cleansers. It is well tolerated and designed to clean effectively while minimizing scalp or skin irritation.

A mild surfactant derived from the amino acid sarcosine and lauric acid, used as a gentle cleanser. It is significantly milder than sulfates, widely used in personal care products, and well tolerated.

A coconut-derived amphoteric surfactant used to boost foam and mildness in cleansers and shampoos. CIR has reviewed it as safe as used, but it is one of the more established contact-allergy triggers in personal care, usually traced to manufacturing impurities such as amidoamine and dimethylaminopropylamine (DMAPA) rather than the betaine itself. People with a history of eyelid or scalp dermatitis are more likely to react.

A wax-like ester of ethylene glycol and stearic acid used purely to thicken shampoo/conditioner and give it a pearly opaque look; it has no cleansing or active role. CIR found it non-sensitizing and non-irritating even at high test concentrations, and decades of manufacturer exposure data show no reported health effects.

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

Another sugar-and-fatty-alcohol derived non-ionic surfactant, structurally close to coco-glucoside but made from a shorter (decyl, C10) fatty chain. It is a gentle cleanser generally well tolerated, though a small number of contact-allergy case reports exist, mostly in people with pre-existing skin conditions.

A sulfate-free surfactant that provides gentle cleansing with a low irritation profile, making it suitable for sensitive skin formulations. It is milder than both sulfate and sulfonate alternatives while remaining effective at removing oils and dirt.

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 positively charged conditioning polymer used in shampoos and conditioners to reduce frizz and improve manageability. It is well tolerated and has been safely used in cosmetics for decades.

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 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 polymer of quaternary ammonium compounds widely used as a conditioning and antistatic agent in hair products. It is well established in cosmetic formulations with a strong safety record in rinse-off applications.

A small humectant and solvent molecule that helps other ingredients dissolve and helps skin hold water. It is one of the most studied cosmetic ingredients and is considered safe at the concentrations used in personal care products.

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

A naturally occurring acid used to preserve and adjust pH in cosmetic formulas. It is generally recognized as safe at cosmetic use levels, with mild irritation possible on broken or very sensitive skin at higher concentrations.

A polyethylene glycol ether of lauryl alcohol, used as a mild surfactant and emulsifier in cleansers and other rinse-off products. CIR assessments support the safety of laureth surfactants in cosmetics, and they are often chosen for their mildness.

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

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, 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.

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.

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

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.

A beta hydroxy acid used to smooth texture and clear pores. Safe at cosmetic levels; can be mildly irritating if overused.

A fast-evaporating solvent used to carry actives and create a light, quick-drying texture in toners and washes. At the concentrations used in rinse-off and brief-contact formulas, it has a well-established safety record, though repeated contact with high-concentration formulas can be drying.

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 plant-derived protein hydrolyzate that functions as a humectant and skin conditioning agent. While generally well tolerated, those with soy sensitivities or allergies should be cautious, as protein hydrolyzates may retain antigenic properties.

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 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.

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

An organic UV filter with a genuinely mixed evidence picture: it is a documented contact and photo-contact allergen in a subset of users, and studies show it absorbs into the bloodstream at levels that prompted the FDA to request further safety data. The EU has lowered its permitted concentration as a precaution. It is not established as unsafe at approved levels, but people with sensitive skin may prefer to watch for reactions or choose a mineral filter.

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 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 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.

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.

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.

Green tea extract is a well-studied topical antioxidant with a long history of use in serums and moisturizers, generally well tolerated at cosmetic concentrations. Panel safety reviews of Camellia sinensis-derived ingredients have not identified meaningful topical hazard.

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.

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

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 plant-derived water or extract used mainly as a soothing humectant filler. Evidence for dramatic skin benefits beyond mild hydration and soothing is limited, but it is well tolerated by most people.

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.