CLIO Superproof Pen Liner
A eyeliner with 25 ingredients.
Eyeliner with 25 ingredients
We independently verify ingredients, backed by peer-reviewed research. Suggest an update.
What's inside
Ingredients List
Butylene Glycol
HumectantPhenoxyethanol
PreservativeDisodium EDTA
Polyglyceryl-3 Disiloxane Dimethicone
Skin ConditioningSodium Hydroxide
BufferingWater
Skin ConditioningCI 77266
Cosmetic ColorantCI 77491
Cosmetic ColorantCI 77492
Cosmetic ColorantPentylene Glycol
Skin ConditioningAlcohol
AntimicrobialCaprylyl Glycol
EmollientMethylparaben
PreservativeSodium Dehydroacetate
PreservativeSodium Polyaspartate
HumectantStyrene/Acrylates Copolymer
Ammonium Acrylates/Methylstyrene/Styrene Copolymer
CI 77499
Cosmetic ColorantEthylhexylglycerin
Skin ConditioningEthylhexyl Acrylate/Methyl Methacrylate Copolymer
Propylparaben
PreservativeBeheneth-30
Cleansing1,2-Hexanediol
Skin ConditioningAcrylates/Octylacrylamide Copolymer
Ammonium Styrene/Acrylates Copolymer
Butylene Glycol, Phenoxyethanol, Disodium EDTA, Polyglyceryl-3 Disiloxane Dimethicone, Sodium Hydroxide, Water, CI 77266, CI 77491, CI 77492, Pentylene Glycol, Alcohol, Caprylyl Glycol, Methylparaben, Sodium Dehydroacetate, Sodium Polyaspartate, Styrene/Acrylates Copolymer, Ammonium Acrylates/Methylstyrene/Styrene Copolymer, CI 77499, Ethylhexylglycerin, Ethylhexyl Acrylate/Methyl Methacrylate Copolymer, Propylparaben, Beheneth-30, 1,2-Hexanediol, Acrylates/Octylacrylamide Copolymer, Ammonium Styrene/Acrylates Copolymer
Benefits
Concerns
Ingredients Explained
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
Learn more about Butylene GlycolPhenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.
On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.
Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.
Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.
Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.
Learn more about PhenoxyethanolDisodium EDTA is a chelating agent. It grabs onto and deactivates metal ions that sneak into your products from water, packaging, or air.
This ingredient mainly works behind the scenes and helps with:
On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.
One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).
Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.
You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.
Learn more about Disodium EDTAPolyglyceryl-3 Disiloxane Dimethicone is a type of silicone.
Sodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.
In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.
"Alkaline" refers to a high pH level. A low pH level would be considered acidic.
Learn more about Sodium HydroxideWater. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!
Learn more about WaterCI 77266 is a high-purity pigment used to create an intense black color in cosmetics. It is made up of fine particles of pure carbon. This ingredient is also often listed as Carbon Black in ingredient lists.
You'll likely find this ingredient in mascaras, eyeliners, brow products, and eye shadow.
In the US, this ingredient can only be used if it meets strict FDA specifications. Certain versions even require batch-by-batch certification after extensive safety evaluation.
In the European Union, this ingredient is permitted as a colorant and classified as a "nanomaterial" based on its particle size (meaning it requires deeper assessment).
The EU Scientific Committee on Consumer Safety (SCCS) has reviewed nano-sized carbon black specifically and concluded that it does not pose a risk to human health when used in cosmetic products applied to healthy, intact skin and formulated to avoid inhalation.
Studies support this regulatory stance. Laboratory studies on nano-carbon black show potential for cytotoxicity and inflammatory effects in immune cells; it is important to highlight these findings are based on in vitro (not done on a living organism) testing or inhalation scenarios rather than normal topical cosmetic use.
Occupational studies involving industrial workers exposed to airborne carbon black have not shown a clear link between cumulative exposure and cancer risk. These findings are not directly applicable to cosmetics; cosmetic formulations bind pigments within creams, gels, and liquids that are not inhaled.
Overall, evidence shows that this ingredient is safe under regulatory guidelines and purity standards, especially when formulated to avoid airborne exposure.
Even with regulatory approval and a long history of use, some consumers might prefer to avoid ingredients that are petroleum-derived or that fall under the “nanomaterial” category.
Choosing whether to use CI 77266 isn’t necessarily about safety alone; it can also be about personal philosophy, comfort level with synthetic versus natural ingredients, and how much weight you place on ongoing research and regulatory oversight.
Makeup is highly individual, and personal preference plays an important role in deciding what feels right for you.
Learn more about CI 77266Ci 77491 is also hydrated iron III oxide. It's sole purpose is to give a red/pink hue to products.
Iron III oxides are classified as inorganic chemicals for coloring.
Synthetically created Ci 77491 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.
Learn more about CI 77491CI 77492 is also hydrated iron III oxide. It's sole purpose is to give a yellow hue to products.
Iron III oxides are classified as inorganic chemicals for coloring.
Synthetically created CI 77492 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.
Learn more about CI 77492Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:
Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.
On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.
Typical use levels in a formula run about 1-5%.
Learn more about Pentylene GlycolThis ingredient is also called ethanol or ethyl alcohol. It is denatured, meaning made undrinkable for cosmetic use.
In formulas, it:
Is it bad for your skin?
The answer comes down to concentration. Patch and wash studies have found highly concentrated alcohol-based hand rubs (60-100%) cause less barrier disruption than washing with a basic detergent like SLS. The only measurable effect in these studies was a temporary dip in skin hydration.
Concentrations below 12-15% in leave-on cosmetics is generally well-tolerated. Concentrations above start to see increased transepidermal water loss (TEWL) and reduced hydration.
In concentrations about 58%, it creates temporary channels in your skin's lipid layers to become more permeable and allow other ingredients to slip through easily.
This ingredient can be up to 80% of the formula in alcohol-based perfumes.
Overall, this ingredient is probably harmless if found lower down an ingredients list but worth side-eyeing if it's high up (especially if your barrier is already struggling).
Alcohol can worsen dry skin, eczema, and oily skin, especially at higher concentrations. This is because it can increase transepidermal water loss and decrease hydration to disrupt the skin barrier.
According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients.
True allergic contact dermatitis to ethanol is uncommon, but be sure to patch test if you have dry or sensitive skin.
Learn more about AlcoholCaprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
Learn more about Caprylyl GlycolMethylparaben is a synthetic preservative and one of the most widely used in the world. It has a simple, but important job: prevent your products from going bad by stopping bacteria, yeast, and mold from growing.
Typical use levels are low, often 0.1-0.3%.
This is also one of the most heavily studied preservatives out there and major regulatory bodies have repeatedly given it the green light.
In 2023, the EU's Scientific Committee on Consumer Safety (SCCS) confirmed that this ingredient is safe up to 0.4% on its own, of up to 0.8% when mixed with other paraben esters.
Here's the science behind the noise behind parabens/hormones as well:
Methylparaben shows very weak estrogen-like activity in vitro tests (more than 1,000x weaker than your body's own estradiol). In vivo (live-organism) studies don't support a meaningful endocrine-disrupting effect either.
You get a stronger estrogenic effect from eating tofu, actually.
It's also a low sensitizer and allergic reactions are uncommon; they usually happen on damage or broken skin.
There is a caveat: France has proposed to formally re-examine its endocrine classification in 2025 so the regulatory conversation isn't fully closed as of yet.
But as it stands today, this ingredient is considered safe at permitted levels.
Learn more about MethylparabenSodium Dehydroacetate is a synthetic preservative and sodium salt form of dehydroacetic acid. It stops bacteria, mold, and yeast from growing in your products at low concentrations.
Clinical testing found it to be non-irritating, non-sensitizing, and non-photosensitizing. It's also not significantly absorbed through skin.
There are a very small number of reported cases of contact dermatitis in cases linked to wound-care creams used over compromised skin (rather than skincare).
Overall, this is a well-studied and low-risk preservative just doing its job.
Typical concentrations run up to 0.6%, which is also the maximum amount permitted under both EU CosIng regulations and US FDA guidelines.
Learn more about Sodium DehydroacetateWe don't have a description for Sodium Polyaspartate yet.
This ingredient is a synthetic polymer that mainly works as a film former. It creates a thin, flexible film on the surface of your skin. Once applied, it helps improves wear, durability, and resistance to water/smudging.
Due to its large molecule size, it sits on top of your skin rather than absorbing into it.
We don't have a description for Ammonium Acrylates/Methylstyrene/Styrene Copolymer yet.
Ci 77499 is also hydrated iron III oxide. It is created from mixing red and black iron oxides. This helps give shades of darkness to a product.
Iron III oxides are classified as inorganic chemicals for coloring.
Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.
Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
Learn more about EthylhexylglycerinWe don't have a description for Ethylhexyl Acrylate/Methyl Methacrylate Copolymer yet.
Propylparaben is a preservative and one of the most widely used members of the paraben family (it's been used in cosmetics for over a century now).
It works by disrupting microbial cell membranes and enzymes, and is a broad-spectrum protector that works exceptionally well against molds, yeasts, and gram-positive bacteria.
You'll likely see it paired with methylparaben to cover the full range (including gram-negative bacteria).
This ingredient is effective at low concentrations (~0.2-0.5%) and stable across a wide pH range (4.5-7.5 pH). It's effectiveness drops off above pH 8 and it can lose potency when combined with non-ionic surfactants like polysorbate 80 due to micellization.
The regulatory bodies have concluded this ingredient to be safe as used in cosmetics. The EU has capped it at 0.14% and combined parabens are not to exceed 0.8%.
While parabens do cross the stratum corneum, only about 1% remains for absorption into the body. This is because most of it is metabolized within living skin.
Learn more about PropylparabenWe don't have a description for Beheneth-30 yet.
1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
It is a:
- Humectant, drawing moisture into the skin
- Emollient, helping to soften skin
- Solvent, dispersing and stabilizing formulas
- Preservative booster, enhancing the antimicrobial activity of other preservatives
We don't have a description for Acrylates/Octylacrylamide Copolymer yet.
We don't have a description for Ammonium Styrene/Acrylates Copolymer yet.
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Where it's from
CLIO is a Korean brand
We're dedicated to providing you with the most up-to-date and science-backed ingredient info out there.
The data we've presented on this page has been verified by a member of the SkinSort Team.
Read more about us· Updated October 31, 2025 • Added by scowls