Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Defense Essential Glow Moisturizer SPF 30 Versus CeraVe AM Facial Moisturising Lotion SPF30

Paula's Choice Defense Essential Glow Moisturizer SPF 30 Versus CeraVe AM Facial Moisturising Lotion SPF30 This brightening moisturizer is formulated around Glycyrrhiza Glabra Root Extract and Tetrapeptide-30 to brighten dull-looking skin and fade the look of

Paula's Choice Defense Essential Glow Moisturizer SPF 30 Versus CeraVe AM Facial Moisturising Lotion SPF30

This brightening moisturizer is formulated around Glycyrrhiza Glabra Root Extract and Tetrapeptide-30 to brighten dull-looking skin and fade the look of dark spots.

This barrier-repair day moisturizer is formulated around Niacinamide and Ceramide NP to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

C12-15 Alkyl Benzoate

Zinc Oxide

Titanium Dioxide

Glycerin

Isononyl Isononanoate

Butylene Glycol

Cetearyl Alcohol

Potassium Cetyl Phosphate

Dimethicone

Glyceryl Stearate

Glycyrrhiza Glabra Root Extract

Actinidia Chinensis Fruit Extract

Argania Spinosa Kernel Oil

Tetrapeptide-30

Linoleic Acid

Resveratrol

Ascorbyl Glucoside

Niacinamide

Tocopheryl Acetate

Magnesium Ascorbyl Phosphate

Bisabolol

Tocopherol

Phospholipids

Lecithin

Glycine Soja Sterols

Xanthophylls

Pullulan

Sodium Gluconate

Xanthan Gum

Sclerotium Gum

Alumina

Caprylic/Capric Triglyceride

Citric Acid

Triethoxycaprylylsilane

C13-14 Isoparaffin

Acrylates Copolymer

Polyhydroxystearic Acid

Caprylyl Glycol

Polyacrylamide

Ceteareth-20

Aluminum Stearate

Laureth-7

Ethylhexylglycerin

Phenoxyethanol

Water, C12-15 Alkyl Benzoate, Zinc Oxide, Titanium Dioxide, Glycerin, Isononyl Isononanoate, Butylene Glycol, Cetearyl Alcohol, Potassium Cetyl Phosphate, Dimethicone, Glyceryl Stearate, Glycyrrhiza Glabra Root Extract, Actinidia Chinensis Fruit Extract, Argania Spinosa Kernel Oil, Tetrapeptide-30, Linoleic Acid, Resveratrol, Ascorbyl Glucoside, Niacinamide, Tocopheryl Acetate, Magnesium Ascorbyl Phosphate, Bisabolol, Tocopherol, Phospholipids, Lecithin, Glycine Soja Sterols, Xanthophylls, Pullulan, Sodium Gluconate, Xanthan Gum, Sclerotium Gum, Alumina, Caprylic/Capric Triglyceride, Citric Acid, Triethoxycaprylylsilane, C13-14 Isoparaffin, Acrylates Copolymer, Polyhydroxystearic Acid, Caprylyl Glycol, Polyacrylamide, Ceteareth-20, Aluminum Stearate, Laureth-7, Ethylhexylglycerin, Phenoxyethanol

Homosalate 10%

Menthyl Anthranilate 5%

Ethylhexyl Methoxycinnamate 5%

Octocrylene 2%

Zinc Oxide 6.3%

Behentrimonium Methosulfate

BHT

Ceramide NP

Ceramide AP

Ceramide EOP

Carbomer

Methylparaben

Sodium Lauroyl Lactylate

Cholesterol

Aluminum Starch Octenylsuccinate

Disodium EDTA

Propylparaben

Hydroxyethylcellulose

Hydrolyzed Hyaluronic Acid

Phytosphingosine

Homosalate 10%, Menthyl Anthranilate 5%, Ethylhexyl Methoxycinnamate 5%, Octocrylene 2%, Zinc Oxide 6.3%, Water, Niacinamide, Glycerin, Cetearyl Alcohol, Behentrimonium Methosulfate, Dimethicone, BHT, Ceramide NP, Ceramide AP, Ceramide EOP, Carbomer, Triethoxycaprylylsilane, Methylparaben, Sodium Lauroyl Lactylate, Cholesterol, Aluminum Starch Octenylsuccinate, Disodium EDTA, Propylparaben, Hydroxyethylcellulose, Hydrolyzed Hyaluronic Acid, Phytosphingosine, Xanthan Gum

Reviews

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.

Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.

Dimethicone 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.

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.

And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

Triethoxycaprylylsilane is a silicon-based surface modifier that makes sunscreens feel silky and makeup stay put.

Its main job is to coat mineral particles like titanium dioxide, zinc oxide, and color pigments in a thin, oily layer so they spread smoothly, don't clump, and stick to skin better.

This ingredient is typically used at low levels (up to 2.5% in eyeshadow and 1% in lipstick).

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.

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!

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.

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.

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.

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03Beeswax is natural wax produced by honey bees to build their honeycomb.
  4. 04Because it forms a protective layer on your skin, it can help lock in moisture and reduce water loss. It is also widely used as a thickener and emulsifier in lip balms and lotions. Research suggests beeswax containing moisturizers can support skin b…
  5. 05In comedogenic testing, Beeswax scored a 0-2, which is on the low end. Whether or not a product clogs your pores really comes down to the formula as a whole (not any single ingredient on its own).
  6. 06Cera Alba is the white, bleached form of this ingredient.
  7. 07Just so you know, beeswax is not vegan since it is animal-derived. It cannot be removed with water, but can be taken off with an oil cleanser.
  8. 08People with a known Propolis allergy also report to have reactions from beeswax.
  9. 09Beeswax's wax esters are derived primarily from palmitic and oleic acid (C16 and C18:1). Both of these fall within the C11-C24 feeding window.
  10. 10The Malassezia yeast can potentially cleave these esters and release usable fatty acids, so this ingredient may not be fungal acne safe. However, not everyone will react to this ingredient.
  11. 11This ingredient is also known as shea butter. It is a plant-derived extract from the nuts of the Africa shea tree and one of the most well-studied emollients.
  12. 12Because it has a high concentration of fatty acids (primarily oleic, stearic, and linoleic) it is able to form a protective barrier on the skin's surface. This helps seal in moisture and prevents transepidermal water loss (TEWL).
  13. 13In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).
  14. 14Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
  15. 15Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
  16. 16While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
  17. 17This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
  18. 18Caprylic/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.
  19. 19Though 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.
  20. 20In practice, that translates to a long shelf life and a consistently elegant skin feel.
Source · skinsort.com
02

Product index

Related product references

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03

Comparison edit

Read side by side