What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningCyclopentasiloxane
EmollientZinc Oxide
Cosmetic ColorantCI 77891
Cosmetic ColorantPropanediol
SolventPolyglyceryl-3 Polydimethylsiloxyethyl Dimethicone
Skin ConditioningDibutyl Adipate
EmollientCaprylyl Methicone
Skin Conditioning1,2-Hexanediol
Skin ConditioningDisteardimonium Hectorite
StabilisingMagnesium Sulfate
Hydrogen Dimethicone
Aluminum Hydroxide
EmollientC30-45 Alkyl Cetearyl Dimethicone Crosspolymer
EmollientPolyglyceryl-2 Dipolyhydroxystearate
Skin ConditioningStyrene/Acrylates Copolymer
Stearic Acid
CleansingHelianthus Annuus Seed Oil
EmollientPentylene Glycol
Skin ConditioningButylene Glycol
HumectantEthylhexylglycerin
Skin ConditioningOctyldodecanol
EmollientCentella Asiatica Extract
CleansingGalactomyces Ferment Filtrate
HumectantAnthemis Nobilis Flower Oil
MaskingEchium Plantagineum Seed Oil
Skin ConditioningSalvia Hispanica Seed Extract
EmollientHouttuynia Cordata Extract
Skin ConditioningFructooligosaccharides
HumectantSaccharide Hydrolysate
HumectantPullulan
Cardiospermum Halicacabum Flower/Leaf/Vine Extract
Skin ConditioningHelianthus Annuus Seed Oil Unsaponifiables
EmollientMadecassoside
AntioxidantDicaprylyl Carbonate
EmollientSorbitan Sesquioleate
EmulsifyingCyclomethicone
EmollientUndecane
EmollientTridecane
PerfumingTocopherol
AntioxidantDimethicone Crosspolymer
Emulsion StabilisingPhenyl Trimethicone
Skin ConditioningWater, Cyclopentasiloxane, Zinc Oxide, CI 77891, Propanediol, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Dibutyl Adipate, Caprylyl Methicone, 1,2-Hexanediol, Disteardimonium Hectorite, Magnesium Sulfate, Hydrogen Dimethicone, Aluminum Hydroxide, C30-45 Alkyl Cetearyl Dimethicone Crosspolymer, Polyglyceryl-2 Dipolyhydroxystearate, Styrene/Acrylates Copolymer, Stearic Acid, Helianthus Annuus Seed Oil, Pentylene Glycol, Butylene Glycol, Ethylhexylglycerin, Octyldodecanol, Centella Asiatica Extract, Galactomyces Ferment Filtrate, Anthemis Nobilis Flower Oil, Echium Plantagineum Seed Oil, Salvia Hispanica Seed Extract, Houttuynia Cordata Extract, Fructooligosaccharides, Saccharide Hydrolysate, Pullulan, Cardiospermum Halicacabum Flower/Leaf/Vine Extract, Helianthus Annuus Seed Oil Unsaponifiables, Madecassoside, Dicaprylyl Carbonate, Sorbitan Sesquioleate, Cyclomethicone, Undecane, Tridecane, Tocopherol, Dimethicone Crosspolymer, Phenyl Trimethicone
Titanium Dioxide 3.1%
Cosmetic ColorantZinc Oxide 11.64%
Cosmetic ColorantWater
Skin ConditioningCyclomethicone
EmollientPropanediol
SolventDicaprylyl Carbonate
EmollientPolyglyceryl-3 Polydimethylsiloxyethyl Dimethicone
Skin ConditioningCetyl Ethylhexanoate
EmollientCI 77891
Cosmetic Colorant1,2-Hexanediol
Skin ConditioningDisteardimonium Hectorite
StabilisingSalvia Hispanica Seed Extract
EmollientCentella Asiatica Extract
CleansingHouttuynia Cordata Extract
Skin ConditioningMagnesium Sulfate
Hydrogen Dimethicone
Aluminum Hydroxide
EmollientPolyglyceryl-2 Dipolyhydroxystearate
Skin ConditioningStearic Acid
CleansingDimethicone Crosspolymer
Emulsion StabilisingPhenyl Trimethicone
Skin ConditioningFructooligosaccharides
HumectantSaccharide Hydrolysate
HumectantPullulan
Helianthus Annuus Seed Oil
EmollientEthylhexylglycerin
Skin ConditioningOctyldodecanol
EmollientAnthemis Nobilis Flower Oil
MaskingEchium Plantagineum Seed Oil
Skin ConditioningButylene Glycol
HumectantGalactomyces Ferment Filtrate
HumectantCardiospermum Halicacabum Flower/Leaf/Vine Extract
Skin ConditioningHelianthus Annuus Seed Oil Unsaponifiables
EmollientPentylene Glycol
Skin ConditioningMadecassoside
AntioxidantTocopherol
AntioxidantCaprylyl Glycol
EmollientTitanium Dioxide 3.1%, Zinc Oxide 11.64%, Water, Cyclomethicone, Propanediol, Dicaprylyl Carbonate, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Cetyl Ethylhexanoate, CI 77891, 1,2-Hexanediol, Disteardimonium Hectorite, Salvia Hispanica Seed Extract, Centella Asiatica Extract, Houttuynia Cordata Extract, Magnesium Sulfate, Hydrogen Dimethicone, Aluminum Hydroxide, Polyglyceryl-2 Dipolyhydroxystearate, Stearic Acid, Dimethicone Crosspolymer, Phenyl Trimethicone, Fructooligosaccharides, Saccharide Hydrolysate, Pullulan, Helianthus Annuus Seed Oil, Ethylhexylglycerin, Octyldodecanol, Anthemis Nobilis Flower Oil, Echium Plantagineum Seed Oil, Butylene Glycol, Galactomyces Ferment Filtrate, Cardiospermum Halicacabum Flower/Leaf/Vine Extract, Helianthus Annuus Seed Oil Unsaponifiables, Pentylene Glycol, Madecassoside, Tocopherol, Caprylyl Glycol
Reviews
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
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
Aluminum Hydroxide is a form of aluminum. It can be naturally found in nature as the mineral gibbsite. In cosmetics, Aluminum Hydroxide is used as a colorant, pH adjuster, and absorbent.
As a colorant, Aluminum Hydroxide may add opacity, or reduce the transparency. Aluminum hydroxide is contains both basic and acidic properties.
According to manufacturers, this ingredient is an emollient and humectant. This means it helps hydrate the skin.
In medicine, this ingredient is used to help relieve heartburn and help heal ulcers.
There is currently no credible scientific evidence linking aluminum hydroxide in cosmetics to increased cancer risk.
Major health organizations allow the use of aluminum hydroxide in personal care products and have not flagged it as a carcinogenic risk at typical usage levels.
Learn more about Aluminum HydroxideThis oil is created by distilling the dried flower heads of the Roman Chamomile flower.
Chamomile is rich in antioxidants and has anti-inflammatory properties. Several compounds found in chamomile help with soothing, such as bisbolol.
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 GlycolCardiospermum halicacabum extract is more commonly known as Balloon Vine Extract.
Centella Asiatica Extract (Centella) is one of the most researched botanical extracts in skincare with decades of studies backing its effects on inflammation, collagen, and the skin barrier.
That research keeps pointing back to the same four triterpenoid saponins: Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid.
These compounds allow centella to dial back inflammation, encourage the skin to build and hold onto collagen, support the barrier and hydration, and bring solid antioxidant activity to protect against signs of aging.
Centella also carries a nice supporting cast of Vitamin A, vitamin C, several B vitamins, and amino acids. Put it all together and you get an ingredient that soothes, hydrates, and protects, all at once.
Most of centella's magic comes from the four big compounds (Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid). These are the actives doing the heavy lifting in almost every centella study.
Here is the short version of what they do in the skin:
So it is not just soothing for the sake of soothing. Centella calms the skin AND helps it rebuild.
Just FYI, not all centella on an ingredient list is the same. What you are getting actually depends on the extract:
Fun fact on the ratios: the leaves tend to be richest in Madecassoside and Asiaticoside, and lower in the two acids. The exact amounts shift with where the plant is grown and how it is processed. This means purity really does vary brand to brand.
Centella is one of the most easygoing actives out there.
It layers well with basically everything: niacinamide, hyaluronic acid, peptides, and vitamin C, and also pairs nicely with stronger actives like retinoids and exfoliating acids where it can help take the edge off irritation.
On the safety side, centella and its triterpenes are classified as weak sensitizers, meaning allergic reactions are possible but uncommon.
Patch tests at 1% and 5% came back negative in test panels, and creams at typical use levels did not cause allergic reactions across large groups of people.
But as with any new active, a patch test is still a smart move for very reactive skin.
Centella is widely used because it is effective at low percentages. For context, human safety testing found no meaningful irritation from creams containing centella extract at everyday use levels (the tested amounts were well under 1%).
The irritancy threshold in animal testing was also above 30% (so real-world formulas sit far below anything concerning).
In collagen lab studies, higher concentrations drove more collagen synthesis, so serums built around centella tend to feature it more prominently.
Bottom line: you will find centella working nicely anywhere from a fraction of a percent up to hero-ingredient levels depending on whether it is a supporting soother or the main event.
Fun fact: Centella has been used as a medicine and in food for many centuries. As a medicine, it is used to treat burns, scratches, and wounds.
Learn more about Centella Asiatica ExtractCi 77891 is a white pigment from Titanium dioxide. It is naturally found in minerals such as rutile and ilmenite.
It's main function is to add a white color to cosmetics. It can also be mixed with other colors to create different shades.
Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.
Learn more about CI 77891Cyclomethicone is a class of silicones used to improve the texture of products.
Their cyclic or circular structure decreases stability. This causes quick evaporation when applied to skin. Cyclomethicones are often used as a carrier for other ingredients. Once it evaporates, it leaves a silky barrier on the skin.
The most popular types of cyclomethicones include D5 and D6.
Learn more about CyclomethiconeDicaprylyl Carbonate comes from carbonic acid and caprylyl alcohol, a fatty alcohol. It is an emollient and gives skin a velvet feel. The sources of Dicaprylyl Carbonate may be synthetic or from animals.
As an emollient, Dicaprylyl Carbonate creates a film on the skin. This film traps moisture in, keeping your skin soft and hydrated.
Dimethicone Crosspolymer is a silicone created by modifying dimethicone with hydrocarbon side chains. Due to its large size, it does not penetrate skin. It is considered non-occlusive.
Dimethicone Crosspolymer is used to stabilize and thicken products. It also helps give products a silky feel.
Disteardimonium Hectorite comes from the clay mineral named hectorite. It is used to add thickness to a product.
It can also help stabilize a product by helping to disperse other ingredients.
Hectorite is a rare, white clay mineral.
Learn more about Disteardimonium HectoriteEchium Plantagineum Seed Oil is an oil and isn't fungal acne safe. It can help to reduce redness.
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 EthylhexylglycerinFructooligosaccharides (FOS) are a type of prebiotic sugar with humectant and skin conditioning properties. As a humectant, they help attract and hold moisture in the skin.
FOS essentially acts as a food source for the "good" bacteria on your skin and make it harder for "bad" bacteria to thrive. A 2022 study using a reconstructured human skin model found that just 1% of FOS was enough to shift the bacteria balance in favor of beneficial species. This suggests it could help support a healthier skin microbiome over time.
This ingredient has a low sensitization risk and testing shows it does not classify as a skin irritant or sensitizer.
FOS are usually produced from sugar beets and can also be found in foods like bananas, garlic, and onions.
Learn more about FructooligosaccharidesGalactomyces Ferment Filtrate (GFF) is a byproduct of fermenting Galactomyces yeast (the same yeast traditionally used to brew sake, Japan's beloved rice wine).
Sake brewers have long been known for their remarkably youthful hands. This is what actually first sparked scientific interest in GFF's skin benefits.
GFF works by stimulating filaggrin production in the skin. Filaggrin is a protein that binds structural proteins in the outer skin layer together to form a tight barrier that shields against allergens, bacteria, and moisture loss.
It's also a key building block of our natural moisturizing factors (NMF), or the network of compounds that keep skin plump and hydrated.
By boosting filaggrin, GFF helps strengthen both our barrier and our skin's ability to retain moisture.
Beyond hydration, GFF has notable antioxidant properties that help protect against oxidative stress and UV-induced inflammation.
Research also suggests it may help regulate sebum and keratin production. This could be an interesting option for those concerned about oiliness or skin texture.
Fungal acne:
This ingredient doesn't contain fatty acids or oils that could feed Malassezia, and the yeast used to make it (Galactomyces) is a different genera of fungi from Malassezia. The presence of one doesn't stimulate the other.
However, there is a concern raised by some communities that this ingredient could trigger a reaction in people who are broadly sensitive to yeast/fungal-derived ingredients.
Learn more about Galactomyces Ferment FiltrateHelianthus Annuus Seed Oil is a plant oil derived from the seeds of a sunflower.
It is rich in fatty acids, primarily linoleic acid and oleic acid. This gives it emollient and skin conditioning properties.
The reason this ingredient is so effective is because it forms a thin film on the skin that reduces transepidermal water loss (TEWL) while supplying linoleic acid to the stratum corneum to improve barrier strength.
The high linoleic acid content is particularly noteworthy for acne-prone skin.
Research suggests that acne-prone skin tends to be deficient in linoleic acid in sebum. Topical application may help replenish this to support a healthier follicular environment and less comedone-promoting sebum.
One randomized study found sunflower seed oil preserved skin barrier integrity in adult volunteers with and without atopic dermatitis (outperforming olive oil).
This ingredient is well-studied, gentle, and an effective emollient suitable for most skin types.
On fungal acne: This ingredient may not be Fungal acne (Malassezia folliculitis) safe. This is because it contains fatty acids with carbon chain lengths in the C11-C24 range.
Learn more about Helianthus Annuus Seed OilThis ingredient is the small fraction of sunflower seed oil (~1.5-2% of the whole oil) that cannot be turned into soap.
This concentrated fraction is rich in skin-nourishing compounds like free fatty acids, tocopherols, and phytosterols. Linoleic acid makes up about 48-74% of its composition.
Unsaponifiables have high antioxidant potential due to the tocopherols, carotenoids, and phenolic acids that help protect skin from free radical damage. On the other hand, linoleic acid supports the skin's barrier by replenishing ceramides and reducing transepidermal water loss.
A manufacturer-sponsored clinical study found that a cream with 2% of this ingredient increased skin moisturization by 48.6% after 1 hour and 34.2% after 24 hours.
Using this cream twice-daily for 4 weeks showed meaningful improvement in dryness, roughness, and desquamation (the shedding of dead skin cells).
Keep in mind this is a small, industry-funded study so it'd be great to see independent replication. However, the mechanism is consistent with well-establish linoleic and phytosterol research.
While this ingredient is generally considered safe, those with an Asteraceae/Compositae plant allergy should patch test this ingredient.
Fungal acne: this ingredient is not considered safe for fungal acne because the Malassezia yeast preferentially metabolizes in the C11-24 range. Linoleic acid falls into this range at C18.
Learn more about Helianthus Annuus Seed Oil UnsaponifiablesHouttuynia Cordata Extract is more commonly known as Heart Leaf, Fish Mint, or Chameleon plant.
The components found in Heart Leaf give it antioxidant, hydrating, antimicrobial, and anti-inflammatory properties.
Heart Leaf is rich in flavonoids such as quercetin, apigenin, and more. It also contains polysaccharides, the most common type of carbs in food.
Flavonoids have been shown to be effective antioxidants. They help neutralize free-radical molecules. Free-radical molecules are unstable molecules that may damage our skin cells and DNA. The flavonoids in Heart Leaf also help soothe the skin.
Polysaccharides are naturally found in our skin. They play a role in hydrating and repairing the top layer of skin. The polysaccharides in Heart Leaf help moisturize our skin.
Studies show decanoyl acetaldehyde, a component of Heart Leaf oil, is effective at killing bacteria.
The name 'Fish Mint' comes from the herb's natural fishy smell. Is is native to southeast Asia and used throughout the continent for traditional cooking and medicine.
Learn more about Houttuynia Cordata ExtractHydrogen dimethicone is a silicone-based ingredient. It is mainly used to alter the texture and spread of a product without adding "stickiness".
Madecassoside is one of four active compounds found in Centella asiatica and is one of the main reasons Centella is so effective at calming irritated skin and supporting the moisture barrier.
There's a solid body of peer-reviewed research backing Madecassoside for several skin benefits. Studies have found:
Madecassoside pairs well with other hydrating or antioxidant ingredients like Ascorbic Acid or Hyaluronic Acid.
Learn more about MadecassosideMagnesium Sulfate is a salt. More specifically, it is an epsom salt, or the bath salt used to help relieve muscle aches.
Despite having ‘sulfate’ in the name, it isn’t a surfactant or cleansing agent like sodium lauryl sulfate. Unlike those sulfates, magnesium sulfate doesn’t have the same cleansing or foaming properties (it's simply a type of salt).
In cosmetics, Magnesium Sulfate is used to thicken a product or help dilute other solids. It is a non-reactive and non-irritating ingredient.
One study shows magnesium deficiency may lead to inflammation of the skin. Applying magnesium topically may help reduce inflammation.
You can find this ingredient in sea water or mineral deposits.
Learn more about Magnesium SulfateOctyldodecanol is a fatty alcohol sourced from plant oils like coconut or palm (or made synthetically).
It is:
You'll likely see this in many BHA products because this is the go-to solvent for salicylic acid.
This ingredient is typically used at levels between 2-20%.
Regarding fungal acne:
In 2019, this ingredient was tested against multiple Malassezia species (the yeast that causes fungal acne) and showed no growth.
Pentylene 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 GlycolPhenyl Trimethicone is a silicon-based polymer. It is derived from silica.
Phenyl Trimethicone is used as an emollient and prevents products from foaming.
As an emollient, it helps trap moisture in the skin. It is considered an occlusive.
Learn more about Phenyl TrimethiconePolyglyceryl-2 Dipolyhydroxystearate isn't fungal acne safe.
Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone is a type of silicone.
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
Learn more about PropanediolPullulan is a low viscosity polysaccharide (a long chain carbohydrate) with binding and film forming properties when dissolved in water. It is used to create a "silicone-like" or silky feel in cosmetics without adding viscosity.
According to a manufacturer, this ingredient's ability to easily dissolves makes it a great carrier for active ingredients.
Due to it being edible and tasteless, you'll likely find this ingredient in breath freshener strips. This ingredient is produced from the starch of the fungus, Aureobasidium pullulans.
Pullulan is stable over a broad-range of pH.
Learn more about PullulanWe don't have a description for Saccharide Hydrolysate yet.
This ingredient comes from chia seeds (the same ones you put in your smoothie!). It has emollient and skin conditioning properties due to its rich concentration of linoleic acid and polyunsaturated fatty acids.
One small clinical study of 10 people found that a 4% chia seed oil formulation significantly improved skin hydration and soothed itchiness in 8 weeks. Another study showed using a chia seed extract enriched with vitamin F told skin cells to produce more of their own hydration factors.
There's also some lab evidence that chia seed extract, when paired with pomegranate extract, may help reduce excess pigment production.
Learn more about Salvia Hispanica Seed ExtractStearic Acid is a fatty acid that is already found in your skin. It's one of the free fatty acids that works alongside ceramides and cholesterols to maintain your barrier.
In cosmetics, it is a multitasker:
Safety-wise, the CIR Expert Panel has concluded it to be safe in cosmetics when formulated to be non-irritating and non-sensitizing.
Free stearic acid is a C18 fatty acid that the Malassezia yeast can substrate, so this ingredient may not be fungal acne safe.
Learn more about Stearic AcidTocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
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.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
Learn more about TocopherolWater. 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 WaterZinc 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