Paula's Choice Smoothing Primer Serum SPF 30 Ingredients Explained

Photostabilizers help stabilize UV-filters and prevents them from degrading quickly.

According to EU regulation, this ingredient can cause harmful effects to aquatic life.

(Part of the reason that sunscreens need to be frequently re-applied is due to the photo instability of many chemical sunscreen filters)

Currently, homosalate is approved in concentrations up to 10% in the EU and 15% in the US. The FDA is currently doing further research on the effects of homosalate, and it is possible that these approved concentrations will change in the future.

The ethylhexanol in this ingredient is a fatty alcohol and helps hydrate your skin, similar to oils. It is an emollient, which means it traps moisture into the skin.

According to manufacturers, Ethylhexyl Salicylate absorbs UV wavelength of 295-315 nm, with a peak absorption at 307-310 nm. UVA rays are linked to long term skin damage, such as hyperpigmentation. UVB rays emit more energy and are capable of damaging our DNA. UVB rays cause sunburn.

Studies have found that avobenzone becomes ineffective when exposed to UV light (it is not photostable; meaning that it breaks down in sunlight). Because of this, formulations that include avobenzone will usually contain stabilizers such as octocrylene.

However, some modern formulations (looking at you, EU!) are able to stabilize avobenzone by coating the molecules.

Avobenzone does not protect against the UV-B range, so it's important to check that the sunscreen you're using contains other UV filters that do!

The highest concentration of avobenzone permitted is 3% in the US, and 5% in the EU.

Bisabolol helps soothe skin. It does this by blocking the inflammatory signals, helping to reduce your body's reaction to irritation.

Bisabolol also interferes with the process of hyperpigmentation. This can help with reducing dark spots and uneven tone.

Bisabolol is an antioxidant. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells. By fighting these free-radicals, Bisabolol may slow down signs of aging.

Studies have shown Bisabolol to have antimicrobial properties and may be a fungicide. These properties help preserve a product's shelf life.

Bisabolol also helps the absorption of other ingredients.

CASE contains several ingredients that protect and soothe skin. These include caffeine, polysaccharides, sucrose, lipids, minerals, and proteins.

The star ingredient in coffee is caffeine.

Caffeine helps with anti-aging, antioxidant, and photo-protection.

How? It has been shown to block collagenase (~41%), elastase (~35%), and tyrosinase (~13%).

Collagenase and elastase are enzymes that break down collagen and elastin, respectively. Tyrosinase is the enzyme that controls melanin production.

Our skin creates melanin when exposed to UV as a defense mechanism.

It should be noted most studies looked at caffeine's ability to inhibit damage from UV-B rays.

According to a manufacturer, this ingredient is often dissolved using water, glycerin, and propanediol. The caffeine content of this ingredient is about 100 ppm.

Coffea Arabica is native to Ethiopia.

Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.

Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.

Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.

Antioxidant components in chamomile make it an effective ingredient to help slow the signs of aging. Antioxidants help fight free-radical molecules, or molecules that may damage your skin.

Essential oils from chamomile have been found to improve wound healing due to its antimicrobial properties.

Ancient Greeks and Egyptians used Chamomile to treat skin redness and dryness. Chamomile has also been used to help treat stomach issues.

As an antioxidant, retinyl palmitate helps neutralize free-radical molecules. These molecules have the potential to damage skin cells. Thus, antioxidants may help with anti-aging.

Retinyl palmitate can be good for be good for oily skin by helping to unclog pores. However, it may not be good for dry skin and fungal acne.

After using this product, you should follow up with sunscreen.

This ingredient is often added to low-fat milk to increase the levels of Vitamin A.

Aloe contains the antioxidants Vitamins A, C, and E. These vitamins neutralize free radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.

The aloe plant is naturally abundant in polysaccharides, a carbohydrate made of sugar molecules. Polysaccharides help hydrate your skin by mimicking your skin's natural carbohydrates.

As it is easily absorbed by the skin, aloe is a great moisturizer. It is both a humectant and emollient. Emollients help trap moisture in your skin, keeping your skin soft. Humectants draw water from the air to your skin.

Other components of aloe include sugars such as monosaccharides and polysaccharides, folic acid, choline, many common minerals such as calcium, fatty acids, amino acids, and Vitamin B12.

Aloe does not protect against UV rays, despite it soothing sunburns.

There are over 420 species of aloe but Aloe Barbadensis is the most commonly used for topical products.

Many components of tea have anti-inflammatory properties. Polyphenols and L-theanine help soothe the skin and reduce irritation. L-theanine is an amino acid that makes up most of the amino acids found in tea leaves. The caffeine in Camellia Sinensis Leaf Extract helps calm inflamed blood vessels.

Camellia Sinensis Leaf Extract also contains Vitamin Bs, linoleic acid, magnesium, calcium, iron, and zinc.

Camellia Sinensis Leaf Extract also has antimicrobial properties.

Research has shown both drinking Camellia Sinensis Leaf Tea and applying it to the skin can help boost skin elasticity and hydration. Studies also show using tea extract may reduce sebum, or oil, production.

Chlorella Vulgaris is made up of lipids, carbohydrates, and chlorophyll.

This ingredient is commonly used as food additive in Japan.

Caprylic Acid has antimicrobial and antifungal properties. Several studies found it to be effective at treating yeast infections. It also has anti-inflammatory properties. Besides cosmetics, this ingredient is also used for a variety of medical purposes such as treating digestive disorders.

This ingredient is minimally soluble in water.

Read more about a similar ingredient Caprylic/Capric Triglyceride.

Last, the phytochemicals found in apples are strong antioxidants. These antioxidants help with anti-aging as they protect your skin cells against oxidative damage.