Nexxus Unbreakable Care Anti-Breakage Shampoo

It is able to lift away oil and grime and make a nice lather without stripping your skin, so it's a good pick for sensitive skin.

Safety-wise, it has a good record. The CIR Expert Panel has concluded this ingredient to be safe in cosmetics and concentrations go up to 11% in leave-on products or 13% in rinse-off products.

Despite being derived from coconut oil, this ingredient is fungal acne safe. It's a water-soluble surfactant with no fatty oils or esters left intact on skin for the Malassezia yeast to feed.

You might see people debate whether Sodium Chloride is comedogenic, but there actually haven't been any comedogenic tests done on it. Either way, the overall formulation of a product matters a lot more than any single ingredient.

You might see this ingredient used in scrubs as a primary exfoliating ingredient.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

This ingredient is often chosen as a biodegradable, gentler-sounding alternative to EDTA. It also pulls double duty as a mild humectant and pH buffer.

Typical use levels sit around 0.1-1% and supplier documents list up to 10% as an acceptable ceiling. Industry data found this ingredient family is mostly used well below 1% in leave on products.

Allergy risk is very low; animal testing has found it to be non-irritating to skin and eyes, mutagenicity assays came back negative, and there are no published reports of allergic contact dermatitis to it.

As a humectant, hydrolyzed keratin helps draw moisture from the air to your hair and skin. This helps keep your skin and hair hydrated.

More research is needed on applying biotin topically. However, taking biotin orally has been shown to help nourish the skin, hair, and nails. They play a role in forming skin-hydrating fatty acids.

Biotin is water-soluble. It can be found in foods such as fish, eggs, dairy, nuts, and meat. Vitamin H stands for "haar" and "haut". These are the German words for hair and skin.

Vitamin E is also prevalent in this ingredient and the most dominant form is gamma-tocopherol.

These compounds give the ingredient emollient and skin conditioning properties that keep the skin soft and hydrated.

There's no regulatory maximum cap for this ingredient so you'll see it across a huge concentration range (100% as a single ingredient facial oil).

On allergies: refined cosmetic-grade oils carry almost no protein. The CIR notes that people allergic to a food generally do not react to the refined oil because the allergenic protein does not partition into it (though cold-pressed grades retain more).

However, it's worth patch testing if you have a stone fruit or tree nut allergy because manufacturer processes for removing the protein can vary.

Malassezia lacks the cytosolic fatty acid synthase gene so the yeast cannot make palmitate on its own and instead uses lipases and phospholipases to release fatty acids from host lipids. Since apricot kernel oil is entirely C16-18 (right in the usable range of C11-24), this ingredient may not be fungal acne safe.

Old rabbit-ear testing did assign this ingredient a comedogenic rating of 1-2. The original author has stated that testing on rabbit ears is not an ideal model for human comedogenicity.

Human testing has proved that any finished product with a comedogenic ingredient won't automatically make you break out; it really comes down to concentration, formula, and your skin.

Just know high-oleic oils tend to feel heavier on oily skin so it's worth patch testing.

Spirulina Platensis also contains Vitamin A, Vitamin E, and proteins.

Fucus Vesiculosus Extract contains antioxidants. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.

Fucus Vesiculosus Extract is also rich in sodium, potassium, and amino acids.

Many different types of algae have different benefits.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.

However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.

The dominant fatty acid is lauric acid (44-54%) and then myristic acid (13-19%). There are also small amounts of caprylic, capric, palmitic, oleic, and linoleic acids.

Human testing from CIR has shown no indication this ingredient to be a primary irritant, sensitizer, or phototoxic compound. It's COSMOS-approved for natural and organic products.

Due to the fatty acid content, this ingredient may not be fungal acne safe. Research has confirmed Malassezia can use lauric acid as a food source.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

This ingredient is considered safe at present practices of use and concentration and repeated insult patch test with 50% Glycol Distearate on 125 subjects found no evidence of skin irritation, hypersensitivity, or acute toxicity.

Typical use concentrations range from 0.1-10%.

Because it's an ester of stearic acid, it falls into the range that Malassezia likes to metabolize. This ingredient may not be fungal acne safe.

For haircare friends: this ingredient is not a silicone.

Citronellol is a modified terpene. Terpenes are unsaturated hydrocarbons found in plants. They make up the primary part of essential oils.

Citronellol is not able to be absorbed into deeper layers of the skin. It has low permeability,

Citronellol is also a natural insect repellent.

There's some lab work behind its reputation; in one study, it acted as an antioxidant and calmed inflammation in human immune cells. But it also killed skin cells (keratinocytes) in a dish.

It stopped damaging those cells and still reduced swelling in mice when the researchers wrapped it in tiny capsules to slow its release.

One study that is quoted out of context frequently: clove oil killed human skin and blood vessel cells at levels as low as 0.03%, and about 73% of that came down to eugenol. Keep in mind those were bare cells sitting in a dish with no skin barrier in the way (which is a lot harsher than what happens on your actual face).

On concentrations, it is restricted to 0.64% in leave-on products + body products, 0.21% in baby + lip products, 2.5% in fine fragrance and 4.9% in rinse-off. Real formulas usually land far below those caps.

Allergy is the actual story with this ingredient. It is one of the eight markers dermatologists use for allergy testing, and the EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

It is also a prohapten, meaning it needs enzymatic activation in skin to become allergenic, so sensitivity varies between people.

Rates are modest but not trivial: in a classic EECDRG multicentre study, 13 of about 1,300 patch-tested patients reacted to eugenol, and in eugenol-allergic subjects the lowest positive patch test concentration was 0.031%, with 56% reacting in a 21-day repeated open application test at 0.5% to 2.7%.

Normal use levels are generally fine if you are not already sensitized.

Geraniol can be found in many essential oils including Rose Oil and Citronella Oil. The scent of Geraniol is often described as "rose-like". Many foods also contain Geraniol for fruit flavoring.

Geraniol can irritate the skin when exposed to air. However, irritation depends on the ability of geraniol to penetrate into the skin. In general, geraniol is not able to penetrate skin easily.

Geraniol is colorless and has low water-solubility. However, it is soluble in common organic solvents.

Like citronellol, it is a natural insect repellent.

2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-

You'll typically see this ingredient used in very small amounts; anything above 0.001% in a leave-on product or 0.01% in a rinse-off has to be named on the label in the EU. The citrus oils that carry it sit around 0.5-1% in a finished formula.

Fresh limonene is a weak allergen; the real issue is that it slowly reacts with air and then breaks down from oxidation to create hydroperoxides (which are strong sensitizers). This is why suppliers are required to keep the peroxide value below 20 mmol.

Positive reactions in people being investigated for eczema vary:

It's worth skipping if you have a known fragrance allergy or a compromised barrier, but the risk is low for most people.

Older or long-opened products are also more likely to bother you than fresh ones due to oxidation.

The EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

Fresh linalool is a weak sensitizer but air exposure turns some of it into hydroperoxides, which are strong sensitizers. Those oxidation products are the actual allergy concern.

Patch-test clinics see positive reactions to linalool hydroperoxides in about 4% to 12% of dermatitis patients depending on country and test concentration.

Resassuringly, one analytical study found hydroperoxide levels in real fragranced products to be orders of magnitude below what induced sensitization in animal studies with no evidence of oxidation building up during normal storage.

The practical takeaway is that linalool is fine for most people but worth avoiding if you have a confirmed fragrance contact allergy or a badly compromised barrier.

Products stored a long time after opening are also the high-risk scenario since that is when oxidation happens.

The scent of linalool is described as floral, spicy tropical, and citrus-like.