What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningTitanium Dioxide
Cosmetic ColorantC12-15 Alkyl Benzoate
AntimicrobialGlycerin
HumectantCaprylic/Capric Triglyceride
MaskingCyclopentasiloxane
EmollientDicaprylyl Carbonate
EmollientCetearyl Alcohol
EmollientPropylene Glycol
HumectantDimethiconol
EmollientGlyceryl Stearate
EmollientCeteareth-20
CleansingCeteareth-12
EmulsifyingCetyl Palmitate
EmollientPotassium Cetyl Phosphate
EmulsifyingPEG-100 Stearate
SurfactantZinc Oxide
Cosmetic ColorantPhenoxyethanol
PreservativeDimethicone
EmollientPanthenol
Skin ConditioningDiethylamino Hydroxybenzoyl Hexyl Benzoate
UV FilterSodium Acrylates Copolymer
Lecithin
EmollientPropanediol
SolventHydrolyzed Glycosaminoglycans
HumectantSodium Hyaluronate
HumectantHydrolyzed Hyaluronic Acid
HumectantHyaluronic Acid
HumectantSodium Hyaluronate Crosspolymer
HumectantScenedesmus Rubescens Extract
Skin ConditioningPentylene Glycol
Skin ConditioningSodium PCA
HumectantEthylhexyl Triazone
UV AbsorberTalc
AbrasiveParfum
MaskingMica
Cosmetic ColorantBis-Ethylhexyloxyphenol Methoxyphenyl Triazine
Skin ConditioningHelianthus Annuus Seed Oil
EmollientTocopheryl Acetate
AntioxidantPhragmites Communis Extract
Skin ConditioningPoria Cocos Extract
Skin ConditioningXanthan Gum
EmulsifyingEthylhexylglycerin
Skin ConditioningTetrasodium EDTA
Butylene Glycol
HumectantPolyhydroxystearic Acid
EmulsifyingBisabolol
AntioxidantAscorbyl Tetraisopalmitate
AntioxidantHydroxyacetophenone
AntioxidantCellulose Gum
Emulsion StabilisingLepidium Sativum Sprout Extract
Skin ConditioningSoy Isoflavones
Skin ConditioningPolysorbate 80
EmulsifyingChlorphenesin
AntimicrobialSodium Polyacrylate
AbsorbentCitric Acid
BufferingCI 77492
Cosmetic ColorantCI 77491
Cosmetic ColorantCI 77499
Cosmetic ColorantWater, Titanium Dioxide, C12-15 Alkyl Benzoate, Glycerin, Caprylic/Capric Triglyceride, Cyclopentasiloxane, Dicaprylyl Carbonate, Cetearyl Alcohol, Propylene Glycol, Dimethiconol, Glyceryl Stearate, Ceteareth-20, Ceteareth-12, Cetyl Palmitate, Potassium Cetyl Phosphate, PEG-100 Stearate, Zinc Oxide, Phenoxyethanol, Dimethicone, Panthenol, Diethylamino Hydroxybenzoyl Hexyl Benzoate, Sodium Acrylates Copolymer, Lecithin, Propanediol, Hydrolyzed Glycosaminoglycans, Sodium Hyaluronate, Hydrolyzed Hyaluronic Acid, Hyaluronic Acid, Sodium Hyaluronate Crosspolymer, Scenedesmus Rubescens Extract, Pentylene Glycol, Sodium PCA, Ethylhexyl Triazone, Talc, Parfum, Mica, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Helianthus Annuus Seed Oil, Tocopheryl Acetate, Phragmites Communis Extract, Poria Cocos Extract, Xanthan Gum, Ethylhexylglycerin, Tetrasodium EDTA, Butylene Glycol, Polyhydroxystearic Acid, Bisabolol, Ascorbyl Tetraisopalmitate, Hydroxyacetophenone, Cellulose Gum, Lepidium Sativum Sprout Extract, Soy Isoflavones, Polysorbate 80, Chlorphenesin, Sodium Polyacrylate, Citric Acid, CI 77492, CI 77491, CI 77499
Water
Skin ConditioningC12-15 Alkyl Benzoate
AntimicrobialZinc Oxide
Cosmetic ColorantTitanium Dioxide
Cosmetic ColorantGlycerin
HumectantIsononyl Isononanoate
EmollientButylene Glycol
HumectantCetearyl Alcohol
EmollientPotassium Cetyl Phosphate
EmulsifyingDimethicone
EmollientGlyceryl Stearate
EmollientGlycyrrhiza Glabra Root Extract
BleachingActinidia Chinensis Fruit Extract
EmollientArgania Spinosa Kernel Oil
EmollientTetrapeptide-30
Skin ConditioningLinoleic Acid
CleansingResveratrol
AntioxidantAscorbyl Glucoside
AntioxidantNiacinamide
SmoothingTocopheryl Acetate
AntioxidantMagnesium Ascorbyl Phosphate
AntioxidantBisabolol
AntioxidantTocopherol
AntioxidantPhospholipids
Skin ConditioningLecithin
EmollientGlycine Soja Sterols
EmollientXanthophylls
Skin ConditioningPullulan
Sodium Gluconate
Skin ConditioningXanthan Gum
EmulsifyingSclerotium Gum
Emulsion StabilisingAlumina
AbrasiveCaprylic/Capric Triglyceride
MaskingCitric Acid
BufferingTriethoxycaprylylsilane
C13-14 Isoparaffin
EmollientAcrylates Copolymer
Polyhydroxystearic Acid
EmulsifyingCaprylyl Glycol
EmollientPolyacrylamide
Ceteareth-20
CleansingAluminum Stearate
Cosmetic ColorantLaureth-7
EmulsifyingEthylhexylglycerin
Skin ConditioningPhenoxyethanol
PreservativeWater, C12-15 Alkyl Benzoate, Zinc Oxide, Titanium Dioxide, Glycerin, Isononyl Isononanoate, Butylene Glycol, Cetearyl Alcohol, Potassium Cetyl Phosphate, Dimethicone, Glyceryl Stearate, Glycyrrhiza Glabra Root Extract, Actinidia Chinensis Fruit Extract, Argania Spinosa Kernel Oil, Tetrapeptide-30, Linoleic Acid, Resveratrol, Ascorbyl Glucoside, Niacinamide, Tocopheryl Acetate, Magnesium Ascorbyl Phosphate, Bisabolol, Tocopherol, Phospholipids, Lecithin, Glycine Soja Sterols, Xanthophylls, Pullulan, Sodium Gluconate, Xanthan Gum, Sclerotium Gum, Alumina, Caprylic/Capric Triglyceride, Citric Acid, Triethoxycaprylylsilane, C13-14 Isoparaffin, Acrylates Copolymer, Polyhydroxystearic Acid, Caprylyl Glycol, Polyacrylamide, Ceteareth-20, Aluminum Stearate, Laureth-7, Ethylhexylglycerin, Phenoxyethanol
Reviews
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient.
It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation.
A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.
In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.
You'll likely see use concentrations quite low, usually 0.1-0.2%.
Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.
Learn more about BisabololButylene 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 GlycolC12-15 Alkyl Benzoate is a lightweight emollient made by combinig benzoic acid with fatty alcohols that are 12-15 carbons long.
In cosmetics, it plays several roles:
The Cosmetic Review Expert Panel has concluded the alkyl benzoate group to be safe as used in cosmetics; it wasn't found to be a skin irritant and unlikely to be absorbed due to its low water solubility.
This report recorded almost 1000 reported uses with concentrations up to 59% in leave-on products but your cosmetics will typically use 0.5-15% depending on the product.
It's often called a "SPF booster": this is because it keeps UV filters properly dissolved and evenly distributed to support a sunscreen's performance. It doesn't actually raise SPF on its own.
Overall, this ingredient is well tolerated.
This ingredient is fungal acne safe because it is an ester of benzoic acid.
Think of this ingredient as two parts stuck together: an oily part and an acid part. Malassezia only gets a meal when it can snip off a fatty acid to eat. With C12-15 Alkyl Benzoate, the acid part is benzoic acid, which isn't a fatty acid and which the yeast can't use as food.
Benzoic acid is actually used as a preservative to stop yeast from growing.
The oily part is a blend of C12-15 fatty alcohols but fatty alcohols in this size range can support only a little Malassezia growth (mostly for one species of Malassezia as well).
In the ingredient, those alcohols stay locked inside the molecule. The yeast can only reach them by snipping the benzoate bond, and that type of bond is harder for it to cut than a normal fatty bond.
So not much gets released. And whatever does get snipped comes packaged with benzoic acid, which discourages yeast growth.
Learn more about C12-15 Alkyl BenzoateCaprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Learn more about Caprylic/Capric TriglycerideCeteareth-20 is an emulsifier and surfactant made by reacting cetearyl alcohol with 20 moles of ethylene oxide.
This gives it both oil and water-loving properties that makes it an effect emulsifier; it's really great at pulling oil droplets into water to create a stable, creamy, and easy-to-spread base.
Typical use ranges from 0.5-30%. Most leave-on products are in the 1-10% zone.
The 20 ethylene oxide units is well above the PEG-10 threshold and therefore not a food source for Malassezia (it's fungal acne safe).
This ingredient has a comedogenic rating of 2 and an irritancy rating of 3. These numbers come from testing the raw ingredient on rabbit ears and doesn't reflect how it will behave in a finished product.
In practice, this ingredient is a well-tolerated ingredient. The ratings reflect cautious lab conditions and not real-world use. Just be sure to patch test any formulas you feel unsure about.
Learn more about Ceteareth-20Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.
Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.
It plays several roles in a formula:
Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.
Multiple assessments have found it to be non-irritating and non-sensitizing to most people.
However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.
Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.
Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.
Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.
This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.
A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.
Learn more about Cetearyl AlcoholCitric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
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.
Read more about some other popular AHA's here:
Learn more about Citric AcidDimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.
What it does:
Dimethicone comes in different viscosities:
Depending on the viscosity, dimethicone has different properties.
Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.
This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.
Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.
Learn more about DimethiconeEthylhexylglycerin 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 EthylhexylglycerinGlycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
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.
Learn more about GlycerinGlyceryl Stearate is made by reacting glycerin with stearic acid (typically sourced from plant oils like palm or coconut). It's an emulsifier, emollient, and mild occlusive.
Emulsifiers help ingredients like oil and water stay mixed so your formula stays nicely blended and uniform in texture.
This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.
A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.
Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.
Fun fact: The human body also creates Glyceryl Stearate naturally.
Learn more about Glyceryl StearateLecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.
Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:
It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.
Learn more about LecithinPhenoxyethanol 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 PhenoxyethanolPolyhydroxystearic Acid is a vegetable-derived soft wax made from castor oil. It's an emulsion stabilizer, thickener, and film former.
You'll likely see it in sunscreens because it helps disperse pigments and UV-reflecting minerals like titanium dioxide and zinc oxide evenly.
Depending on the concentration, it can drastically change the texture of a product from pasty solid (like lipstick) to sprayable liquid.
The CIR Expert Panel for Cosmetic Ingredient Safety has concluded this ingredient to be safe in cosmetics. The highest reported use concentration is 14.2% in lipsticks.
Learn more about Polyhydroxystearic AcidPotassium Cetyl Phosphate is the potassium salt of a mixture. This mixture consists of the esters from phosphoricacid and cetyl alcohol.
Potassium Cetyl Phosphate is an emulsifier and cleansing agent. Emulsifiers help stabilize a product. It does this by preventing certain ingredients from separating.
As a cleansing agent, Potassium Cetyl Phosphate helps gather oils, dirts, and pollutants from your skin. This makes it easier to rinse them away with water.
Learn more about Potassium Cetyl PhosphateTitanium Dioxide (TD) is a mineral UV filter widely used in sunscreens and cosmetics.
It's one of only two UV filters officially classified as "mineral" by regulatory agencies (the other being Zinc Oxide).
A really common myth is that mineral filters work by reflecting UV light off your skin like tiny mirrors.
They don't only do that; modern research shows TD protects mostly by absorbing UV radiation, the same way chemical filters do.
When researchers measured this, reflection accounted for only about 4-5% of the protection (and less than SPF 2 on its own). The other ~95% comes from absorption: the UV photons hit the particle and their energy gets soaked up by its semiconductor band gap rather than bouncing off.
So "reflects vs. absorbs" was never really the right way to split mineral from chemical filters.
TD gives broad-spectrum protection that's strongest in the UVB and UVA-2 range and weaker in the UVA-1 range. Its UVA protection isn't quite as strong as Zinc Oxide's which is why you'll often see the two paired together.
Together, they make a solid broad-spectrum system.
TD is a great pick for sensitive, acne-prone, or redness-prone skin because it's non-irritating and chemically inert. Regulatory reviews classify it as a non-sensitizer and mild-to-non-irritant.
It's also unlikely to cause the "eye sting" some chemical filters are known for.
The main trade-off is cosmetic; TD can leave a white cast and has a thicker texture. This is why mineral sunscreens are often less cosmetically elegant than chemical or hybrid formulas (and harder to shade-match on deeper skin tones).
Formulators often use micronized or nano-sized TD to cut down on white case and improve spreadability. Smaller particles scatter less visible light so the formula looks less chalky while still filtering UV.
TD is almost always bundled with coatings like Alumina, Silica, Stearic Acid, or Dimethicone. These coatings do two important jobs:
TD can be used at up to 25% in a finished sunscreen; this is the regulatory ceiling in both the US and the EU.
In practice, the amount in any given product varies a lot depending on the target SPF and whether it's paired with other UV filters.
TD is one of the most heavily vetted sunscreen ingredients out there. It is approved as a UV filter in all major markets worldwide, including the US, EU, UK, Japan, Korea, China, Australia, and Canada.
The safety evidence is solid. There was an old worry that nano particles might absorb through skin into the body but multiple studies (including on damaged, sunburned, and UV-irradiated skin) have shown that TD stays on the surface and the layer of dead skin cells on top of everything else.
There's also no evidence of carcinogenicity, mutagenicity, or reproductive toxicity from dermal exposure of this ingredient.
For those who have seen the headline about a 2022 EU ban on TD, that was on TD as a food additive (a complete separate use from topical sunscreen).
There are ongoing questions about how nano-TD might affect marine ecosystems. As of now, there has been no conclusive evidence that any form of TD (or any other sunscreen filter) harms coral reefs or marine life.
The science is still developing and it's a space worth watching rather than packing over.
However, several destinations have reef-safety sunscreen rules that restrict certain chemical filters and steer visitors toward mineral, non-nano options. If you're traveling somewhere with these rules, a non-nano mineral sunscreen is the safe bet.
Learn more about Titanium DioxideTocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.
Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.
The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.
Most leave-on skincare keeps it at the lower end, often between 0.5-1%.
Learn more about Tocopheryl AcetateWater. 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 WaterXanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.
Learn more about Xanthan GumZinc Oxide (ZO) is a mineral broad-spectrum UV filter and the broadest-spectrum filter recognized by the FDA. It covers everything from UVB through to long-wave UVA.
On top of sun protection, it has skin protectant and skin-soothing properties too.
Here's a myth worth busting: mineral filters are usually described as working by "reflecting" or "bouncing" UV off your skin.
That's mostly not true: when researchers actually measured it, ZO and Titanium Dioxide reflect only about 4-5% of UV (less than SPF 2 worth of protection).
The vast majority of the work (~95%) is done by absorption, similar to chemical UV filters. ZO is a semiconductor that absorbs UV photos through its energy band gap.
So the old "physical blocker vs. chemical absorber" framing is really an oversimplification.
Zinc Oxide is one of the most effective broad-spectrum UV filters out there. It protects across UVB, UVA2, and UVA1 with a flat, even absorption curve across the whole UVA-UVB range.
That uniform UVA coverage is its standout feature; titanium dioxide skews more toward UVB as its particle size drops so ZO gives more consistent and extended UVA protection.
It's also very photostable. As an inorganic oxide, ZO doesn't break down in sunlight the way some organic filters can, so it holds up over a day of wear.
This ingredient is gentle and soothing, making it go-to for sunscreens aimed at sensitive skin, rosacea, or ecezma-prone skin, babies, and children.
It's also unlikely to cause the "eye sting" that some sunscreen ingredients are known for, and regulatory agencies broadly consider it non-toxic and safe for topical use.
Beyond sun protection, ZO is also a recognized OTC skin protectant. It forms a breathable barrier that shields skin from moisture and irritation while supporting healing. This is why you'll see it as a classic active in diaper rash creams.
The only downside to ZO is that it can leave a visible white cast, especially on deeper skin tones. This is the main reason mineral sunscreens have historically felt less cosmetically elegant than chemical or hybrid formulas.
Zinc Oxide comes in both non-nano and nano forms. The dividing line is 100nm and anything under is classified as a nanomaterial by the EU.
The nano version scatters less visible light which cuts down white case and gives a lighter, more wearable texture.
Another thing worth understanding about formulation:
Uncoated ZO has some inherent photocatalytic activity. This just means it can generate reactive oxygen species under UV. It's exactly why cosmetic-grade ZO is almost always surface-coated; this coating suppresses that reactivity and improves how the powder disperses and feels.
A well-formulated coated ZO largely sidesteps this issue.
Zinc Oxide is commonly used anywhere from 10% up to the regulatory maximum in sunscreens (25%).
Mineral-only broad-spectrum products often land in the 15-25% range to hit higher SPF and UVA values. Keep in mind SPF performance depends heavily on particle size, dispersion, and the rest of the formula, and not just the percentage.
As an OTC skin protectant like diaper creams, ZO typically runs higher at roughly 10-40%.
This ingredient is generally easy to work with and doesn't photodegrade.
The only thing to know is that uncoated ZO can be a bit reactive in a formula.
Under UV, it can break down sensitive ingredients like other actives or UV filters. This is another reason coated versions are standard. ZO can also react with very acidic ingredients or throw off stability of some creams. A good formula will get around this with the right coatings and dispersion.
The EU's Scientific Committee on Consumer Safety has concluded that ZO nanoparticles "can be considered to not pose any risk of adverse effects in humans after application on healthy, intact or sunburnt skin".
You might hear that ZO is "toxic"; this is because an in-vitro (test tube) study suggested micronized ZO had potential phototoxicity. In vivo (human) investigations have disputed this and the results have come back reassuring.
So does ZO penetrate skin? The short answer is no, not in any way that matters.
The most relevant evidence comes from real-world human studies: in one, volunteers applied ZO nanoparticle sunscreen hourly for six hours and daily for five days. The advanced imaging showed the particles stayed on the surface and never reached the living epidermis, and no cellular toxicity was found.
Other in-vivo and ex-vivo work agree; ZO nanoparticles don't cross the stratum corneum, even on flexed, massaged, or barrier-impaired skin.
A small amount of solubilized zinc ions can dissolve off the particles and enter the upper skin. But the quantities are tiny compared to the zinc already naturally present in your body, and studies haven't found this to cause local toxicity.
The sunscreen bans you've heard of (like Hawaii's) are aimed at two chemical filters, Oxybenzone and Octinoxate. ZO itself it not banned and is often recommended instead.
So far, there's no solid evidence that any form of ZO harms reefs. It is an ongoing and active area of study, and worth keeping an eye on.
If you're traveling somewhere with these rules, a non-nano mineral sunscreen is the safe bet.
Learn more about Zinc Oxide