What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningCamellia Sinensis Leaf Extract
AntimicrobialCyclopentasiloxane
EmollientEthylhexyl Methoxycinnamate
UV AbsorberZinc Oxide
Cosmetic ColorantTitanium Dioxide
Cosmetic ColorantNiacinamide
SmoothingHippophae Rhamnoides Water
MaskingCyclohexasiloxane
EmollientButylene Glycol
HumectantCetyl PEG/PPG-10/1 Dimethicone
EmulsifyingEthylhexyl Salicylate
UV AbsorberIsoamyl P-Methoxycinnamate
UV AbsorberDiphenylsiloxy Phenyl Trimethicone
Skin ConditioningBis-Ethylhexyloxyphenol Methoxyphenyl Triazine
Skin ConditioningLactobacillus/Soybean Ferment Extract
Skin ConditioningBifida Ferment Filtrate
Skin ConditioningSodium Chloride
MaskingSodium Hyaluronate
HumectantUndecane
EmollientButyl Methoxydibenzoylmethane
UV AbsorberSorbitan Sesquioleate
EmulsifyingEuphorbia Cerifera Wax
Sorbitan Olivate
EmulsifyingSynthetic Beeswax
Emulsion StabilisingDisteardimonium Hectorite
StabilisingCI 77492
Cosmetic ColorantTridecane
PerfumingDipropylene Glycol
HumectantHydroxyacetophenone
AntioxidantTrihydroxystearin
Skin ConditioningTriethoxycaprylylsilane
Chlorphenesin
AntimicrobialCaprylyl Glycol
EmollientCI 77491
Cosmetic ColorantDimethicone
EmollientPropylene Carbonate
SolventCI 77499
Cosmetic ColorantAdenosine
Skin ConditioningDisodium EDTA
Camellia Japonica Flower Extract
EmollientSqualane
EmollientLithospermum Officinale Root Extract
Skin ConditioningChamomilla Recutita Flower Extract
MaskingTocopheryl Acetate
AntioxidantPanthenol
Skin ConditioningPanax Ginseng Root Extract
EmollientDipotassium Glycyrrhizate
HumectantTocopherol
AntioxidantCynara Scolymus Leaf Extract
Skin ConditioningPolymnia Sonchifolia Root Juice
Skin ConditioningCichorium Intybus Root Extract
MaskingGlycine
Buffering1,2-Hexanediol
Skin ConditioningSerine
MaskingGlutamic Acid
HumectantAspartic Acid
MaskingLeucine
Skin ConditioningAlanine
MaskingLysine
Skin ConditioningArginine
MaskingTyrosine
MaskingPhenylalanine
MaskingValine
MaskingThreonine
Proline
Skin ConditioningIsoleucine
Skin ConditioningHistidine
HumectantMethionine
Skin ConditioningCysteine
AntioxidantWater, Camellia Sinensis Leaf Extract, Cyclopentasiloxane, Ethylhexyl Methoxycinnamate, Zinc Oxide, Titanium Dioxide, Niacinamide, Hippophae Rhamnoides Water, Cyclohexasiloxane, Butylene Glycol, Cetyl PEG/PPG-10/1 Dimethicone, Ethylhexyl Salicylate, Isoamyl P-Methoxycinnamate, Diphenylsiloxy Phenyl Trimethicone, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Lactobacillus/Soybean Ferment Extract, Bifida Ferment Filtrate, Sodium Chloride, Sodium Hyaluronate, Undecane, Butyl Methoxydibenzoylmethane, Sorbitan Sesquioleate, Euphorbia Cerifera Wax, Sorbitan Olivate, Synthetic Beeswax, Disteardimonium Hectorite, CI 77492, Tridecane, Dipropylene Glycol, Hydroxyacetophenone, Trihydroxystearin, Triethoxycaprylylsilane, Chlorphenesin, Caprylyl Glycol, CI 77491, Dimethicone, Propylene Carbonate, CI 77499, Adenosine, Disodium EDTA, Camellia Japonica Flower Extract, Squalane, Lithospermum Officinale Root Extract, Chamomilla Recutita Flower Extract, Tocopheryl Acetate, Panthenol, Panax Ginseng Root Extract, Dipotassium Glycyrrhizate, Tocopherol, Cynara Scolymus Leaf Extract, Polymnia Sonchifolia Root Juice, Cichorium Intybus Root Extract, Glycine, 1,2-Hexanediol, Serine, Glutamic Acid, Aspartic Acid, Leucine, Alanine, Lysine, Arginine, Tyrosine, Phenylalanine, Valine, Threonine, Proline, Isoleucine, Histidine, Methionine, Cysteine
Water
Skin ConditioningCyclopentasiloxane
EmollientCI 77891
Cosmetic ColorantZinc Oxide
Cosmetic ColorantDiphenylsiloxy Phenyl Trimethicone
Skin ConditioningPentaerythrityl Tetraethylhexanoate
EmollientCyclohexasiloxane
EmollientButyloctyl Salicylate
Skin ConditioningGlycerin
HumectantLauryl PEG-9 Polydimethylsiloxyethyl Dimethicone
Skin ConditioningNiacinamide
SmoothingPentylene Glycol
Skin ConditioningMica
Cosmetic Colorant1,2-Hexanediol
Skin ConditioningPEG-10
HumectantDimethicone
EmollientCetyl PEG/PPG-10/1 Dimethicone
EmulsifyingSilica
AbrasiveDisteardimonium Hectorite
StabilisingMagnesium Sulfate
CI 77492
Cosmetic ColorantDiphenyl Dimethicone
EmollientTribehenin
EmollientTriethoxycaprylylsilane
Dimethicone/Vinyl Dimethicone Crosspolymer
Skin ConditioningCI 77491
Cosmetic ColorantAluminum Hydroxide
EmollientCI 77499
Cosmetic ColorantCeresin
Emulsion StabilisingParfum
MaskingEthylhexylglycerin
Skin ConditioningAdenosine
Skin ConditioningPhenyl Trimethicone
Skin ConditioningStearyl Dimethicone
EmollientTrisodium Ethylenediamine Disuccinate
Butylene Glycol
HumectantTocopherol
AntioxidantPentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
AntioxidantGlycine
BufferingSerine
MaskingGlutamic Acid
HumectantAspartic Acid
MaskingLeucine
Skin ConditioningActinidia Polygama Fruit Extract
Skin ConditioningAlanine
MaskingLysine
Skin ConditioningArginine
MaskingTyrosine
MaskingPhenylalanine
MaskingProline
Skin ConditioningThreonine
Valine
MaskingIsoleucine
Skin ConditioningDimethylsilanol Hyaluronate
HumectantHistidine
HumectantHydrolyzed Hyaluronic Acid
HumectantHydrolyzed Sodium Hyaluronate
Skin ConditioningCysteine
AntioxidantMethionine
Skin ConditioningHyaluronic Acid
HumectantPotassium Hyaluronate
Skin ConditioningSodium Hyaluronate
HumectantHydroxypropyltrimonium Hyaluronate
Sodium Hyaluronate Crosspolymer
HumectantSodium Hyaluronate Dimethylsilanol
HumectantSodium Acetylated Hyaluronate
HumectantWater, Cyclopentasiloxane, CI 77891, Zinc Oxide, Diphenylsiloxy Phenyl Trimethicone, Pentaerythrityl Tetraethylhexanoate, Cyclohexasiloxane, Butyloctyl Salicylate, Glycerin, Lauryl PEG-9 Polydimethylsiloxyethyl Dimethicone, Niacinamide, Pentylene Glycol, Mica, 1,2-Hexanediol, PEG-10, Dimethicone, Cetyl PEG/PPG-10/1 Dimethicone, Silica, Disteardimonium Hectorite, Magnesium Sulfate, CI 77492, Diphenyl Dimethicone, Tribehenin, Triethoxycaprylylsilane, Dimethicone/Vinyl Dimethicone Crosspolymer, CI 77491, Aluminum Hydroxide, CI 77499, Ceresin, Parfum, Ethylhexylglycerin, Adenosine, Phenyl Trimethicone, Stearyl Dimethicone, Trisodium Ethylenediamine Disuccinate, Butylene Glycol, Tocopherol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Glycine, Serine, Glutamic Acid, Aspartic Acid, Leucine, Actinidia Polygama Fruit Extract, Alanine, Lysine, Arginine, Tyrosine, Phenylalanine, Proline, Threonine, Valine, Isoleucine, Dimethylsilanol Hyaluronate, Histidine, Hydrolyzed Hyaluronic Acid, Hydrolyzed Sodium Hyaluronate, Cysteine, Methionine, Hyaluronic Acid, Potassium Hyaluronate, Sodium Hyaluronate, Hydroxypropyltrimonium Hyaluronate, Sodium Hyaluronate Crosspolymer, Sodium Hyaluronate Dimethylsilanol, Sodium Acetylated Hyaluronate
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.Â
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 preservativesÂ
Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.
Adenosine has many benefits when used. These benefits include hydrating the skin, smoothing skin, and reducing wrinkles. Once applied, adenosine increases collagen production. It also helps with improving firmness and tissue repair.
Studies have found adenosine may also help with wound healing.
In skincare products, Adenosine is usually derived from yeast.
Learn more about AdenosineAlanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.
Arginine is a semi-essential amino acid. This just means our bodies can product a bit on its own, but sometimes needs a little boost from food sources.
It is a part of your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.
Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.
A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.
Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.
One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.
Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.
Learn more about ArginineAspartic Acid is an amino acid that our bodies produce naturally. It is an antioxidant.
Our body uses Aspartic Acid to help build collagen and elastin. It also plays a role in hydrating skin.
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 GlycolThis ingredient is a silicone-based emulsifer that helps the water and oil phases play nicely together. It's so effective because one end of the molecule loves oil and the other one loves water.
Besides holding formulas together, it also leaves a silky and lightweight feel on skin without the greasiness. A manufacturer also claims it can help with the controlled release of active ingredients.
The CIR Expert Panel found this ingredient to not be sensitizing in concentrations up to 15% in human maximazation testing and dimethicone-based compounds were not comedogenic.
It has a high molecular weight well above 1,000 g/mol which means it limits meaningful skin penetration.
A 2019 study specifically tested this ingredient and found no observable Malassezia growth in its presence.
Learn more about Cetyl PEG/PPG-10/1 DimethiconeCi 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 77492Ci 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.
Cyclohexasiloxane is a type of silicone more commonly known as D6. It is an emollient and solvent.
Cyclohexasiloxane is used to evenly distribute ingredients throughout the product. When applied to the skin, Cyclohexasiloxane evaporates and leaves behind a silky feel.
As an emollient, it can help the skin feel soft and hydrated. It is also used to reduce frizz in hair products.
Learn more about CyclohexasiloxaneCyclopentasiloxane, or D5, is a silicone used to improve texture of products and trap moisture.
D5 is considered lightweight and volatile. Volatile means it evaporates quickly after application. Once evaporated, D5 leaves a thin barrier that helps keep skin hydrated.
It is also an emollient. Emollients help soften the skin and prevent water loss. Silicones create a silky texture in products. D5 helps other ingredients become more spreadable.
Studies show D5 is safe to use in skincare products. We recommend speaking with a skincare professional if you have concerns.
Learn more about CyclopentasiloxaneCysteine is an amino acid found in our bodies. It becomes an antioxidant when converted into gluthatione.
Once it becomes gluthatione, it prevents oxidative damage to parts of our cell. Gluthatione has also been shown to protect our skin from UV-B induced damage.
Dimethicone 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 DimethiconeDiphenylsiloxy Phenyl Trimethicone is a silicone. It has a high refractive index and adds shine to formulations.
According to the safety review by the Cosmetic Ingredient Review (CIR) Expert Panel, it is safe for use in cosmetics under the current practices and concentrations.
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 HectoriteGlutamic Acid is an amino acid that is found in all living organisms. Our bodies use this to help nerve cells in the brain communicate with other cells.
In cosmetics, glutamic acid is a famous humectant. It draws water from the air to your skin, keeping your skin hydrated (like hyaluronic acid).
An in-vitro study from 2024 found glutamic acid to play a role in inhibiting inflammation and thus a potential skin-soothing ingredient.
Other studies show it to be have potential wound healing, skin barrier repair, and hair growth properties.
Glutamic acid has poor solubility in water and other solvents.
Learn more about Glutamic AcidGlycine is the smallest amino acid and a key building block of collagen. It's part if your skin's Natural Moisturizing Factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.
A study from 2022 found that an amino acid complex featuring taurine, arginine, and glycine significantly reduced skin irritation, improved redness, and accelerated the skin repair process.
Histidine is a semi-essential amino acid used by our bodies to create protein. It has humectant and skin conditioning properties.
Our bodies use histidine to create filaggrin - filaggrin is a structural protein that the skin uses in maintaining skin barrier.
One study found histidine and carnosine to be a dynamic duo for your skin:
Oral histidine has also been found to help with filaggrin-deficit skin disorders such as atopic dermatitis.
Why is it considered a semi-essential amino acid? This is because adults are able to create it but children must get it from their diet.
Learn more about HistidineIsoleucine is an amino acid that helps reinforce our skin barrier. This amino acid plays a role in creating protein for the body.
Fun fact: Isoleucine is found in meat, fish, dairy, legumes, and nuts.
We don't have a description for Leucine yet.
Lysine is an essential amino acid (your body cannot make it on its own). It has skin conditioning properties and one of the key players in collagen synthesis.
When your body creates collagen, lysine is basically the glue that holds everything together. It helps collagen fibers lock into each other and stay strong, with vitamin C being its trusty sidekick. Without enough lysine, this glue gets flimsy and less firm, resulting in less bouncy skin.
In skincare, lysine is mostly there to help keep your skin moisturized. It carries water through your skin's layers so everything stays plump.
So will putting lysine on your face create bouncier skin?
It's hard to say; most of the exciting collagen research on lysine comes from oral supplements or lab studies on mice. Further research is needed to truly understand what role topical lysine plays in skincare and your skin.
However, there's no harm in adding lysine to your routine as a supportive and hydrating ingredient.
Learn more about LysineMethionine is an essential amino acid. It is a conditioning agent and commonly found in both skin and hair products.
This amino acid is a precursor to glutathione, a powerful antioxidant.
Fun fact: Methionine can be found in meat, fish, and dairy. It cannot be naturally produce and requires dietary intake.
Learn more about MethionineNiacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.
And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.
You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.
In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.
If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.
When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.
When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.
In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).
Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.
Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.
The type of niacinamide used in skincare is synthetically created.
Learn more about NiacinamidePhenylalanine is an amino acid. It is a skin soothing and hydrating ingredient. Amino acids play a crucial role in wound healing and skin hydration.
This ingredient is also used to help even out skin tone due to its ability to disrupt the melanin production process.
Two structures of phenylalanine exist: L-phenylalanine and D-phenylalanine. L-phenylalanine is essential, this means our bodies cannot produce it naturally and we must get it from foods. Our bodies convert D-phenylalanine to neurotransmitters, and D-phenylalanine is found in our bodies naturally.
Some foods that contain L-phenylalanine include eggs, soybeans, beef, milk.
Learn more about PhenylalanineProline is a non-essential amino acid, meaning your body can make it on its own. In skincare, it is a skin conditioning ingredient that keeps skin soft and hydrated.
It makes up about 23% of the collagen molecule (collagen is the protein responsible for keeping your skin firm) and is involved in your skin's natural hyaluronic acid production. When applied topically, proline can penetrate the skin fairly well due to its small molecular size.
Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.
Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.
Learn more about ProlineSerine is a non-essential amino acid (your body makes it on its own!). It is a major player in your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.
Serine is one of your NMF's most abundant components that works as a skin-identical humectant. Its hydroxyl group grabs onto water molecules to boost hydration without any heaviness or occlusion.
Research on a hydrogel with serine confirmed this serine got delivered to your stratum corneum and demonstrated enhanced skin moisturization.
Interestingly serine also helps your skin produce filaggrin, a protein that keeps your skin barrier strong and used to create collagen.
Learn more about SerineSodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.
In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.
Interestingly, the size of the molecule affects its behavior:
Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.
Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.
You'll typically see concentrations between 0.1-2% for this ingredient.
Learn more about Sodium HyaluronateThreonine is an amino-acid. It helps hydrate the skin and has antioxidant benefits.
Our skin uses threonine for creating collagen and elastin. Humans are not able to create threonine and must get it through eating foods such as fish, lentils, poultry, sesame seeds, and more.
Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.
Vitamin E also helps keep your natural skin lipids healthy. Your lipid skin barrier naturally consists of lipids, ceramides, and fatty acids. Vitamin E offers extra protection for your skin’s lipid barrier, keeping your skin healthy and nourished.
Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.
You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.
There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.
Learn more about TocopherolTriethoxycaprylylsilane is a silicon-based surface modifier that makes sunscreens feel silky and makeup stay put.
Its main job is to coat mineral particles like titanium dioxide, zinc oxide, and color pigments in a thin, oily layer so they spread smoothly, don't clump, and stick to skin better.
This ingredient is typically used at low levels (up to 2.5% in eyeshadow and 1% in lipstick).
Learn more about TriethoxycaprylylsilaneTyrosine is one of the amino acids used to create protein. It plays a role in melanin production.
A study from 2012 found tyrosine to show promising results in restoring skin volume.
Valine is an essential amino acid. It is used by our bodies for tissue repair and muscle growth.
An essential amino acid is one in which our bodies cannot naturally produce so we must get them through diet. Foods such as eggs, dairy, red meat, and fish contain valine.
This ingredient can either be derived from an animal product or be synthetically created.
Learn more about ValineWater. 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 is a mineral broad-spectrum UV filter; it is the broadest UVA and UVB reflector approved by the FDA. It also has skin protectant and skin soothing properties.
Zinc oxide is one of the most effective broad-spectrum UV filters. It protects against UVB, UVAII, and UVAI. In comparison to its counterpart titanium dioxide, zinc oxide provides uniform and extended UVA protection.
Another great benefit? This ingredient is highly photostable so it won't degrade easily under sunlight.
A common myth is that mineral UV filters are widely believed to primarily reflect UV light.
However, modern research shows titanium dioxide absorbs UV radiation like chemical filters (~95% absorption & 5% reflection).
Zinc oxide has great skin soothing properties so you'll likely find this in sunscreens formulated for sensitive skin or babies/children. It is unlikely to cause "eye sting" like other sunscreen ingredients.
Regulatory agencies consider zinc oxide to be non-toxic and safe. It has also been shown to not penetrate the skin.
Unfortunately, this ingredient does leave a visible white cast. This is why mineral sunscreens are often less cosmetically elegant than chemical or hybrid ones.
In cosmetics, zinc oxide can be found in both non-nano and nano-sized forms. The nano version is used to reduce white cast and improve the texture of sunscreen formulas.
There are ongoing concerns surrounding nano-zinc oxide's impact on marine ecosystems and whether it can be absorbed into skin.
Regarding marine ecosystems and coral reefs, there is no conclusive evidence that any form of zinc oxide (or any other sunscreen ingredients) will cause harm. The science is still developing but many consumers are keeping a close eye on this issue.
Please note, many destinations have reef-safety sunscreen rules. For instance, the U.S. Virgin Islands advises all visitors to use non-nano mineral sunscreens.
There has also been some stir about whether micronized or nano zinc oxide has potential photoxicity and absorption through the skin/lungs.
An in-vitro (done in a test tube or petri dish) study demonstrated micronized zinc oxide to have potential phototoxicity. There's no need to fret; the EU Commission's Scientific Committee on Consumer Safety has stated, "The relevance of these findings needs to be clarified by appropriate investigations in vivo." Or in other words, further studies done on living organisms are needed to prove this.
Current research shows zinc oxide nanoparticles do not penetrate intact or sunburned skin. They either remain on the surface or in the outermost layer of dead skin (stratum corneum).
Zinc oxide is one of only two classified mineral UV filters with titanium dioxide being the other one.
Fun fact: Zinc has been used throughout history as an ingredient in paint and medicine. An Indian text from 500BC is believed to list zinc oxide as a salve for open wound. The Ancient Greek physician Dioscorides has also mentioned the use of zinc as an ointment in 1AD.
Learn more about Zinc Oxide