La Roche-Posay Uvidea Anthelios Tone-Up Rosy SPF50+ Versus SkinCeuticals Ultra Facial UV Defense Sunscreen SPF50

Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.

A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.

Drometrizole Trisiloxane is a UV filter that provides both UV-A (344 nm) and UV-B (303 nm) protection.

This ingredient is photostable and studies show it to be generally safe and effective. The compound Meroxyl XL is owned by L'Oreal while Drometrizole trisiloxane can be found in other sunscreen brands.

Ecamsule is a UV-A absorber (290–400 nm) patented by L'Oreal. It is derived from benzylidene camphor, making it highly photostable.

Ecamsule is able to prevent UV from reaching the skin. It absorbs UV and releases it as thermal energy.

Propylene Glycol is an odorless, colorless liquid. As a humectant, it helps skin retain moisture. It also aids in delivering active ingredients.

Another role of this ingredient is preventing a product from melting or freezing. Propylene glycol also adds antimicrobrial properties to a product, elongating product lifespan.

Alcohol Denat. is an alcohol with a denaturant property. It is created by mixing ethanol and other additives. It has a low molecular weight and will evaporate quickly. This helps other ingredients become better absorbed and dry once applied.

Alcohol Denat. is volatile and may cause irritation. It helps draw out natural oils in skin and dry out your skin.

Triethanolamine is an emulsifier and pH adjuster. It is created using ethylene oxide and ammonia. This gives Triethanolamine a nitrogen core and a similar scent to ammonia.

As an emulsifier, it prevents ingredients from separating and enhances texture by adding volume to a product.

Stearic Acid is a fatty acid. It is an emollient, emulsifier, and texture enhancer.

As an emollient, stearic acid helps soften skin. It aids the skin's protective barrier by preventing water loss. It also provides a gentle cleansing effect without stripping away natural oils.

Potassium 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.

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.

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.

You might know this ingredient as Tinosorb S or Bemotrizinol. It is a UV filter that covers both UVA and UVB rays.

Bemotrizinol has two peak UV absorption peaks ( 310 and 340 nm) and is able to absorb both UV-A and UV-B rays. Skin exposed to UV causes free-radical molecules to form. This ingredient works by preventing the UV from reaching your skin.

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

• It is a solvent, meaning that it helps to dissolve other ingredients. This also enhances the absorption of the product into one's skin.
• It is a humectant, which means that it helps attract moisture into the skin.
• It helps improve product application.

Overall, Butylene Glycol is a safe and well-rounded ingredient. It is unlikely to irritate skin, and works well with pretty much all other ingredients.

Caprylyl Glycol is a humectant and emollient, meaning it attracts and preserves moisture.

It is a common ingredient in many products, especially those designed to hydrate skin. The primary benefits are retaining moisture, skin softening, and promoting a healthy skin barrier.

Carbomer is a polymer of acrylic acid. Its main role is to create gel consistency within products.

Carbomer is commonly found in many types of cosmetics products. It is found to be safe in concentrations up to 15%. However, a high amount of carbomer can cause pilling or balling up of products. Most products contain 1% of less of carbomer.

Cetyl Alcohol is a fatty alcohol. Fatty Alcohols are most often used as an emollient or to thicken a product.

Cetyl Alcohol is not related to SD alcohol, denatured alcohol, or ethyl alcohol. The FDA allows products labeled "alcohol-free" to have fatty alcohols.

Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) is a chemical UVA absorber. It is formulated for high UVA protection (320-400 nm) and photostability.

DHHB has been approved by the EU, Japan, Taiwan, and South America for use up to 10%.

Glyceryl Stearate is a mix of glycerin and stearic acid.

Glyceryl Stearate is used to stabilize the mixing of water and oil ingredients. By preventing these ingredients from separating, it can help elongate shelf life. It can also help thicken the product's texture.

Palmitic Acid is a fatty acid found in our skin. In cosmetics, it is usually derived from palm oil. It is a cleanser, emollient, and emulsifier.

As an emollient, it helps hydrate the skin. The emulsifying properties keep ingredients together in a product.

Peg-100 Stearate is an emollient and emulsifier. PEGS are a hydrophilic polyether compound . There are 100 ethylene oxide monomers in Peg-100 Stearate. Peg-100 Stearate is polyethylene glycol ester of stearic acid.

Peg-100 Stearate helps keep skin soft by trapping moisture in. It helps prevent oil and water from separating in a product. By binding oil and water, it helps remove dirt and oil to be rinsed away.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent germ and microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Tromethamine is an aliphatic compound. An aliphatic compound is an organic compound with open-chained carbon atoms. It is synthetically created. Tromethamine is used to balance pH and improve texture.

As an emulsifier, Tromethamine prevents oil and water ingredients from separating. This helps stabilize the product and elongate a product's shelf life. Tromethamine also makes a product thicker.

Xanthan 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.