Scalp Sync Clarifying Shampoo

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

A common foaming cleanser, milder than SLS. Fine for most people in a rinse-off product.

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

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 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.

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.

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.

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.

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.

This small glycol is used to thin out formulas and help preservatives work better, similar in role to propylene glycol and butylene glycol already in wide use. Industry and EU safety reviewers have set purity and concentration conditions for its use rather than restricting it outright, and no consumer-relevant hazard has been established at typical cosmetic levels.

The smallest and most penetrating alpha hydroxy acid, used to loosen the bonds between dead skin cells for smoother texture and tone. It is a genuine irritant at higher concentrations or low pH, can increase sun sensitivity, and the EU restricts free acid content and requires sunscreen-use wording on labeling.

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.

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

A naturally occurring compound from peppermint and other mint plants that creates a cooling sensation and may have mild antimicrobial properties. It is generally safe in rinse-off products and low concentrations but can irritate or sensitize some individuals, particularly in leave-on formulas or higher amounts.

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 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 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 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.

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

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

Amyl cinnamal is a synthetic jasmine-like fragrance material on the EU list of allergens requiring disclosure. It has shown sensitizing potential in some human and animal studies, so fragrance-sensitive users may want to check the label.

A humectant sugar alcohol that draws water into the skin. It is well tolerated and widely used in skincare and food. Not known to cause concern at the concentrations 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.

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.

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.