Peter Thomas Roth Max Vitamin D-Fense Sunscreen Serum Broad Spectrum SPF 50 Ingredients Explained

Octocrylene protects skin from sun damage. It absorbs UV-B with peak absorption of 304 nm. It is a common sunscreen ingredient and often paired with avobenzone, a UVA filter. This is because octocrylene stabilizes other sunscreen ingredients by protecting them from degradation when exposed to sunlight. Octocrylene is a photostable ingredient and loses about 10% of SPF in 95 minutes.

Octocrylene also acts as an emollient, meaning it helps skin retain moisture and softens skin. It is oil-soluble and hydrophobic, enhancing water-resistant properties in a product.

Water. 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.

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.

Polyglyceryl-6 Stearate isn't fungal acne safe.

Squalane is an emollient that helps the skin hold onto moisture. It's an oily liquid that occurs naturally in certain types of fish and plant oils.

Because squalane boosts hydration in the skin, it also comes with plenty of benefits: it is an antioxidant and can help fight free radicals and skin damage. Squalane is also found to have a detoxifying effect when applied.

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.

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.

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.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Sodium Citrate helps maintain the pH of a product. Normal pH level of skin is slightly acidic (~4.75-5.5). The acidity of our skin is maintained by our glands and skin biome. Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

Polyglyceryl-6 Behenate isn't fungal acne safe.

Bioflavonoids are secondary metabolites found in plants. They contain antioxidants.

Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.

Glycoproteins can be good for be good for dry skin.

Cetearyl alcohol is a mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is mainly used as an emulsifier. Emulsifiers help prevent the separation of oils and products. Due to its composition, it can also be used to thicken a product or help create foam.

Cetearyl alcohol is an emollient. Emollients help soothe and hydrate the skin by trapping moisture.

Sodium Phytate is the synthetic salt form of phytic acid. Phytic acid is an antioxidant and can be found in plant seeds.

Sodium Phytate is a chelating agent. Chelating agents help prevent metals from binding to water. This helps stabilize the ingredients and the product.

Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).

If you spot Citric Acid near the end of an ingredient list, it's likely there as a pH adjuster rather than an active ingredient.

Panthenol (also referred to as pro-vitamin B5) is a common ingredient that helps hydrate and soothe the skin.

lt is a humectant, meaning that it helps the skin attract and retain moisture.

Fructooligosaccharides is an alternative sweetener. It is often derived from the blue agave plant.

Fructooligosaccharides is a prebiotic and helps to hydrate the skin. Emerging studies are also showing fructooligosaccharides to have antioxidant properties.

Pentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.

The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.

Tocopheryl Acetate is AKA Vitamin E. It is an antioxidant and protects your skin from free radicals. Free radicals damage the skin by breaking down collagen.

One study found using Tocopheryl Acetate with Vitamin C decreased the number of sunburned cells.

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

Potassium sorbate is potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Ubiquinone (Coenzyme Q10) is a molecule already found in our bodies. It is a potent antioxidant and skin-soothing ingredient.

Aging and environmental exposure diminishes our skin's natural ubiquinone levels. This is much like our natural collagen and elastin.

Guar gum is made from the guar bean, a plant native to India. It is considered a form of polysaccharide and naturally contains sugar.

This ingredient is often used to thicken a product or create a gel-like consistency.

Phytic Acid is a gentle AHA and antioxidant. The chemical makeup makes it classified as an AHA, such as lactic acid.

AHAs are chemical exfoliants that help remove dead skin cells. Phytic Acid has a slight exfoliating effect. Phytic Acid has been shown to help calm irritation. In some cases, it is a chelating agent. Chelating agents help prevent metals from binding to water, helping to stabilize the ingredients in a product.