Alastin SilkSHIELD All Mineral Sunscreen SPF 30 with TriHex Technology
A sunscreen with 20 ingredients, including spf, vitamin E, and peptides.
This mineral sunscreen covers the full UV range and blocks ~97% of UVB at SPF 30.
We independently verify ingredients, backed by peer-reviewed research. Suggest an update.
What's inside
Ingredients List
Zinc Oxide 19.95%
Cosmetic ColorantDimethicone
EmollientCyclopentasiloxane
EmollientPolysilicone-11
Squalane
EmollientPolyglyceryl-3 Polydimethylsiloxyethyl Dimethicone
Skin ConditioningHdi/Trimethylol Hexyllactone Crosspolymer
Methyl Methacrylate Crosspolymer
Triethoxysilylethyl Polydimethylsiloxyethyl Hexyl Dimethicone
Skin ConditioningPalmitoyl Hexapeptide-12
Skin ConditioningPalmitoyl Tripeptide-1
Skin ConditioningDunaliella Salina Extract
Skin ConditioningEctoin
Skin ConditioningHydroxymethoxyphenyl Decanone
Skin ConditioningTocopherol
AntioxidantCaprylic/Capric Triglyceride
MaskingStearalkonium Hectorite
Gel FormingDisteardimonium Hectorite
StabilisingPentaerythrityl Tetraisostearate
EmollientPropylene Carbonate
Solvent
Active Ingredients:
Zinc Oxide 19.95%
Inactive Ingredients:
Dimethicone, Cyclopentasiloxane, Polysilicone-11, Squalane, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Hdi/Trimethylol Hexyllactone Crosspolymer, Methyl Methacrylate Crosspolymer, Triethoxysilylethyl Polydimethylsiloxyethyl Hexyl Dimethicone, Palmitoyl Hexapeptide-12, Palmitoyl Tripeptide-1, Dunaliella Salina Extract, Ectoin, Hydroxymethoxyphenyl Decanone, Tocopherol, Caprylic/Capric Triglyceride, Stearalkonium Hectorite, Disteardimonium Hectorite, Pentaerythrityl Tetraisostearate, Propylene Carbonate
Key Ingredients
Benefits
Concerns
Ingredients Explained
Zinc 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 OxideDimethicone 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 DimethiconeCyclopentasiloxane (D5) is a lightweight silicone that mostly acts as an emollient and solvent in cosmetics. Its the reason your products feel silky, fast-spreading, and non-greasy.
Since D5 is volatile, it does its thing and then evaporates off the skin quickly.
The safety profile of this ingredient is reassuring; the US CIR Expert Panel concluded D5 is safe as used in cosmetics and Health Canada concluded that D5 is not harmful to human health or the environment as currently used in cosmetics
There's a study that people mention about D5 in a rat study showing tumors. This study is related to long-term inhalation of high D5 levels.
Regulatory bodies have judged this study to be not applicable in topical skincare since skin absorption of D5 is very low and we're not really inhaling huge amounts of D5.
The only restriction for this ingredient is environmental. The European Chemicals Agency (ECHA) restricted D5 in wash-off cosmetics at or above 0.1% due to their persistence in water.
Learn more about CyclopentasiloxanePolysilicone-11 is a film-forming silicone that creates a non-tacky and matte finish on the skin. It's commonly used to improve texture, absorb excess oil, and help active ingredients spread evenly.
Due to its "rubber-like" structure, it stays on the skin's surface instead of being absorbed. On the skin, it creates a flexible layer that enhances wearability and stability.
Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).
It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.
This is due to how structurally similar it is to what your skin already produces.
Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.
Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.
No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).
Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.
This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.
The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.
Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.
A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.
The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.
Learn more about SqualanePolyglyceryl-3 Polydimethylsiloxyethyl Dimethicone is a type of silicone.
This ingredient is a powder used to improve texture, slip, and give products a silky texture.
This ingredient comes as a powder made up of small, porous, microbeads. It is used to add a silky feel to products and also helps absorb oil.
Triethoxysilylethyl Polydimethylsiloxyethyl Hexyl Dimethicone is a type of silicone.
Palmitoyl Hexapeptide-12 is a synthetic lipopeptide. This just means it's a short chain of six amino acids with a palmitic acid molecule attached to one end.
The palmitoyl group increases the lipophilicity, helping it penetrate the lipid-rich outer layer of skin more effectively.
Once inside, it helps with keeping skin springy and firm. It works by mimicking the skin repair signals your skin naturally sends out when it's damaged and telling it to kick into rebuild mode.
Studies have shown it can help strengthen the skin barrier as well so it's useful beyond just anti-aging.
In vitro studies suggest it can switch on genes that help skin cells grow, move around, and rebuild skin structure. Just keep in mind most of the strong evidence is from lab studies rather than large-scale clinical trials.
Lab studies suggest it can switch on genes that help skin cells grow, move around, and rebuild skin structure.
This ingredient is usually used at very low concentrations (0.002% in leave-on products).
Fungal acne note:
Usually a palmitic acid component can feed Malassezia in unbound form, but here is is covalently bonded to the peptide. This means it is very difficult for Malassezia to access, and therefore very unlikely to cause fungal acne.
Palmitoyl Tripeptide-1 (aka Pal-GHK) is a synthetic signal peptide made of three amino acids attached to palmitic acid.
That fatty acid attachment is the key: it boosts the peptide's ability to penetrate the skin barrier. This puts it closer to the dermal cells where it can actually make a difference.
Once there, it acts as a matrikine, a signaling peptide that prompts fibroblasts to produce more collagen, fibronectin, and hyaluronic acid.
In vitro studies show it can boost collagen production in skin cells even when UV-damaged skin samples were treated with it at a tiny concentration (it almost fully restored dermal collagen at 5ppm). It achieved this at 100x lower concentration than retinoic acid, which needed 500 ppm to do the same thing.
Human clinical data is promising, but modest:
A study of 23 female volunteers found a small but statistically significant increase (~4%) in skin thickness after treatment at 4 ppm.
A separate small trial of 15 women showed statistically significant reductions in wrinkle length, depth, and skin roughness after applying it twice daily for four weeks.
You'll likely see Pal-GHK paired with Palmitoyl Tetrapeptide-7 as part of the Matrixyl 3000 complex.
Fungal acne note:
Usually a palmitic acid component can feed Malassezia in unbound form, but here is is covalently bonded to the peptide. This means it is very difficult for Malassezia to access, and therefore very unlikely to cause fungal acne.
We don't have a description for Dunaliella Salina Extract yet.
Ectoin is a compound found naturally in some species of bacteria. It can be synthetically created for skincare use.
This ingredient is an osmolyte; Osmolytes help organisms survive osmotic shock (it protects them from extreme conditions). It does this by influencing the properties of biological fluids within cells.
When applied to the skin, ectoin helps bind water molecules to protect our skin. The water forms a sort of armor for the parts of our skin cells, enzymes, proteins, and more.
Besides this, ectoin has many uses in skincare:
A study from 2004 found ectoin to counteract the damage from UV-A exposure at different cell levels. It has also been shown to protect skin against both UV-A, UV-B rays, infrared light, and visible light.
Studies show ectoin to have dual-action pollution protection: first, it protects our skin from further pollution damage. Second, it helps repair damage from pollution.
In fact, ectoin has been shown to help with:
Fun fact: In the EU, ectoin is used in inhalation medication as an anti-pollution ingredient.
Ectoin is a highly stable ingredient. It has a wide pH range of 1-9. Light, oxygen, and temperature do not affect this ingredient.
The chemical name for this ingredient is Tetrahydromethylpyrimidine Carboxylic Acid.
Learn more about EctoinHydroxymethoxyphenyl Decanone is a synthetically created molecule made to mimic ginger extract.
Ginger has anti-inflammatory properties and helps to soothe skin.
According to one study, it is an HA booster, antioxidant, and anti-irritant.
In this study, this ingredient was able to stimulate higher hyaluronic acid levels of the dermal and epidermal layers on a skin-like model. Hyaluronic Acid is a humectant, which means it helps attract moisture to your skin. Humectants help keep skin hydrated.
As an antioxidant, Hydroxymethoxyphenyl Decanone is able to fight off damage from free-radical molecules.
Learn more about Hydroxymethoxyphenyl DecanoneTocopherol 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 TocopherolCaprylic/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 TriglycerideStearalkonium Hectorite is a clay-derived ingredient used to thicken a product and help create a gel-like texture.
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 HectoritePentaerythrityl Tetraisostearate is a synthetic emollient and "skin-feel" ingredient that spreads well and leaves a non-sticky finish with high gloss.
In makeup, it also doubles as a pigment-wetting agent for better color payoff.
It's a well-vetted ingredient for safety and does not penetrate into skin due to its large molecule size.
Because it's a long-chain fatty acid ester, this ingredient may not be fungal acne or Malassezia safe.
Learn more about Pentaerythrityl TetraisostearateThis ingredient is a solvent. It helps dissolve active ingredients and alter the texture of products.
Propylene Carbonate is commonly used in makeup and with clay, such as montmorillonite or bentonite.
Studies show this ingredient to be safe for cosmetics. When it is undiluted, it can cause skin irritation. (It is always diluted in skincare and makeup). This ingredient is water-soluble.
Propylene Carbonate is created from propylene glycol and carbonic acid.
Learn more about Propylene CarbonateReviews
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Where it's from
Alastin is a American brand
30 SPF Rating
With an SPF rating of 30, this product protects against 96.7% of UVB rays
Often compared with
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 September 29, 2025 • Added by katiemarie.g