ISDIN Fotoprotector Fusion Water SPF 50 Versus SkinCeuticals Ultra Facial UV Defense Sunscreen SPF50
What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningOctocrylene
UV Absorber
Ethylhexyl Salicylate
UV Absorber
Propanediol
Solvent
Butyl Methoxydibenzoylmethane
UV Absorber
Polymethyl Methacrylate
Dimethicone
Emollient
Phenylbenzimidazole Sulfonic Acid
UV Absorber
Polysilicone-15
UV Filter
Propylene Glycol Dicaprylate/Dicaprate
EmollientTromethamine
BufferingBis-Ethylhexyloxyphenol Methoxyphenyl Triazine
Skin Conditioning
Silica
Abrasive
Dimethicone/Vinyl Dimethicone Crosspolymer
Skin Conditioning
1,2-Hexanediol
Skin Conditioning
Polysorbate 60
Emulsifying
PEG-10 Dimethicone
Skin Conditioning
Sodium Hyaluronate
Humectant
Tocopheryl Acetate
Antioxidant
Xanthan Gum
EmulsifyingCaprylyl Glycol
Emollient
Parfum
Masking
Disodium EDTA
PEG-8
HumectantTocopherol
Antioxidant
Tropolone
Skin ConditioningAscorbyl Palmitate
Antioxidant
Ascorbic Acid
Antioxidant
Citric Acid
Buffering
Water, Octocrylene, Ethylhexyl Salicylate, Propanediol, Butyl Methoxydibenzoylmethane, Polymethyl Methacrylate, Dimethicone, Phenylbenzimidazole Sulfonic Acid, Polysilicone-15, Propylene Glycol Dicaprylate/Dicaprate, Tromethamine, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Silica, Dimethicone/Vinyl Dimethicone Crosspolymer, 1,2-Hexanediol, Polysorbate 60, PEG-10 Dimethicone, Sodium Hyaluronate, Tocopheryl Acetate, Xanthan Gum, Caprylyl Glycol, Parfum, Disodium EDTA, PEG-8, Tocopherol, Tropolone, Ascorbyl Palmitate, Ascorbic Acid, Citric Acid
Water
Skin ConditioningEthylhexyl Methoxycinnamate
UV Absorber
Drometrizole Trisiloxane
UV Absorber
Glycerin
Humectant
Propylene Glycol
Humectant
Dimethicone
Emollient
Titanium Dioxide
Cosmetic Colorant
Alcohol Denat.
Antimicrobial
Pentylene Glycol
Skin Conditioning
Terephthalylidene Dicamphor Sulfonic Acid
UV Absorber
Diethylamino Hydroxybenzoyl Hexyl Benzoate
UV Filter
Triethanolamine
BufferingBis-Ethylhexyloxyphenol Methoxyphenyl Triazine
Skin Conditioning
Stearic Acid
Cleansing
Potassium Cetyl Phosphate
EmulsifyingTocopherol
Antioxidant
Sodium Cocoyl Sarcosinate
Cleansing
Phenoxyethanol
Preservative
PEG-100 Stearate
Surfactant
Palmitic Acid
Emollient
Xanthan Gum
EmulsifyingTromethamine
BufferingCaprylyl Glycol
Emollient
Carbomer
Emulsion StabilisingDisodium EDTA
Cetyl Alcohol
Emollient
Butylene Glycol
Humectant
Butyrospermum Parkii Seedcake Extract
Skin Protecting
Aluminum Hydroxide
EmollientGlyceryl Stearate
Emollient
Water, Ethylhexyl Methoxycinnamate, Drometrizole Trisiloxane, Glycerin, Propylene Glycol, Dimethicone, Titanium Dioxide, Alcohol Denat., Pentylene Glycol, Terephthalylidene Dicamphor Sulfonic Acid, Diethylamino Hydroxybenzoyl Hexyl Benzoate, Triethanolamine, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Stearic Acid, Potassium Cetyl Phosphate, Tocopherol, Sodium Cocoyl Sarcosinate, Phenoxyethanol, PEG-100 Stearate, Palmitic Acid, Xanthan Gum, Tromethamine, Caprylyl Glycol, Carbomer, Disodium EDTA, Cetyl Alcohol, Butylene Glycol, Butyrospermum Parkii Seedcake Extract, Aluminum Hydroxide, Glyceryl Stearate
Reviews
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
This ingredient is better known as bemotrizinol or Tinosorb S and is one of the best broad-spectrum UV filters in modern sunscreen.
It works by absorbing UV light across a whole range (280-400 nm) with peaks around 310 nm (UVB) and 340-345 nm (UVA). This means it covers UVB plus the deeper UVA wavelengths that drive photoaging and pigmentation.
Another pro?
It's exceptionally photostable, barely degrades in sunlight, and acts as a "bodyguard" for less stable filters.
That's why you'll see it paired with avobenzone or octinoxate; this team up ensures they keep working through sun exposure.
Safety reviews have been reassuring across the board. This ingredient shows low absorption through the skin, rarely irritates, and lab studies found it doesn't act like a hormone in the body (a concern that's been raised about some older sunscreen filters).
On maximum concentrations:
In 2026, the US F.D.A finally added it as an OTC sunscreen ingredient at concentrations up to 6% for adults / children 6 months and older
Learn more about Bis-Ethylhexyloxyphenol Methoxyphenyl TriazineCaprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
Learn more about Caprylyl GlycolDimethicone 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 DimethiconeDisodium EDTA is a chelating agent. It grabs onto and deactivates metal ions that sneak into your products from water, packaging, or air.
This ingredient mainly works behind the scenes and helps with:
On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.
One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).
Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.
You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.
Learn more about Disodium EDTATocopherol 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 TocopherolTromethamine (aka THAM) is a synthetic amino acid that shows up in skincare as a helper ingredient.
It functions as a pH adjuster to help neutralize acidic ingredients and set a formula's pH to the right spot.
This matters a lot because a lot of actives (like vitamin C) needs a specific pH to work well and feel comfortable on skin.
Concentration use ranges from 0.1-1.0% depending on the formula.
Learn more about TromethamineWater. 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 Gum
