Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

CeraVe Skin Renewing Retinol Serum Versus Olay Regenerist Retinol 24 + Peptide Night Moisturizer

CeraVe Skin Renewing Retinol Serum Versus Olay Regenerist Retinol 24 + Peptide Night Moisturizer This anti-aging serum is formulated around Ceramide NP and Niacinamide to soften the look of wrinkles and refine skin texture. This anti-aging night moisturizer is

CeraVe Skin Renewing Retinol Serum Versus Olay Regenerist Retinol 24 + Peptide Night Moisturizer

This anti-aging serum is formulated around Ceramide NP and Niacinamide to soften the look of wrinkles and refine skin texture.

This anti-aging night moisturizer is formulated around Retinol and Niacinamide to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Caprylic/Capric Triglyceride

Potassium Cetyl Phosphate

Hydrogenated Palm Glycerides

Polysorbate 20

PEG-40 Stearate

Cyclopentasiloxane

Hydroxyethylcellulose

Potassium Phosphate

Ceramide NP

Ceramide AP

Ceramide EOP

Carbomer

Niacinamide

Isoceteth-10

Dimethicone/Vinyl Dimethicone Crosspolymer

Triethanolamine

Cetearyl Alcohol

Behentrimonium Methosulfate

Cichorium Intybus Root Extract

Lecithin

Retinol

Silica

Sodium Lauroyl Lactylate

Cholesterol

Phenoxyethanol

Tocopherol

Alcohol

Hydroxyacetophenone

Citric Acid

Hydrolyzed Hyaluronic Acid

Pentylene Glycol

Xanthan Gum

Phytosphingosine

Butyrospermum Parkii Butter

Ethylhexylglycerin

Water, Glycerin, Caprylic/Capric Triglyceride, Potassium Cetyl Phosphate, Hydrogenated Palm Glycerides, Polysorbate 20, PEG-40 Stearate, Cyclopentasiloxane, Hydroxyethylcellulose, Potassium Phosphate, Ceramide NP, Ceramide AP, Ceramide EOP, Carbomer, Niacinamide, Isoceteth-10, Dimethicone/Vinyl Dimethicone Crosspolymer, Triethanolamine, Cetearyl Alcohol, Behentrimonium Methosulfate, Cichorium Intybus Root Extract, Lecithin, Retinol, Silica, Sodium Lauroyl Lactylate, Cholesterol, Phenoxyethanol, Tocopherol, Alcohol, Hydroxyacetophenone, Citric Acid, Hydrolyzed Hyaluronic Acid, Pentylene Glycol, Xanthan Gum, Phytosphingosine, Butyrospermum Parkii Butter, Ethylhexylglycerin

Dimethicone

Tapioca Starch

Dimethicone Crosspolymer

Retinyl Propionate

Palmitoyl Pentapeptide-4

Polyacrylamide

C13-14 Isoparaffin

DMDM Hydantoin

Laureth-4

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Laureth-7

Dimethiconol

Polymethylsilsesquioxane

Aminomethyl Propanol

Titanium Dioxide

Disodium EDTA

Iodopropynyl Butylcarbamate

Water, Dimethicone, Glycerin, Tapioca Starch, Dimethicone Crosspolymer, Retinol, Retinyl Propionate, Niacinamide, Palmitoyl Pentapeptide-4, Polyacrylamide, C13-14 Isoparaffin, DMDM Hydantoin, Polysorbate 20, Laureth-4, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Laureth-7, Dimethiconol, Polymethylsilsesquioxane, Aminomethyl Propanol, Titanium Dioxide, Disodium EDTA, Iodopropynyl Butylcarbamate, Caprylic/Capric Triglyceride

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.

Caprylic/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.

Though 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.

In practice, that translates to a long shelf life and a consistently elegant skin feel.

While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.

Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.

This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.

This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.

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.

Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

Retinol is one of the most studied anti-aging ingredients in skincare (and for good reason!).

It's a form of vitamin A that your skin converts into Retinoic Acid, the active molecule that actually does the work in your cells.

That conversion happens in two steps: your skin first turns Retinol into Retinaldehyde (also called Retinal), then turns Retinaldehyde into Retinoic Acid.

Retinol is converted to biologically active retinoic acid via retinaldehyde by dehydrogenases in a two-step oxidation process.

Each step is a little "upgrade" toward the active form which is part of why Retinol is gentler than prescription Retinoic Acid; your skin does the work gradually. This also explains where Retinol sits in the retinoid family.

Here is the retinoid family ranked roughly by strength: Retinyl Esters (like Retinyl Palmitate) < Retinol < Retinaldehyde < Retinoic Acid.

Retinoid activity increases in that order, while tolerance runs in reverse; retinyl esters are the gentlest and retinoic acid the most irritating.

The more conversion steps an ingredient needs, the gentler (and slower) it tends to be, so Retinol lands in a nice middle spot. It's more effective than the esters, gentler than prescription options.

Once it becomes Retinoic Acid, it binds to receptors inside your cells' nuclei (called RARs and RXRs). These receptor pairs bind to specific DNA motifs called retinoic acid response elements and act like switches that turn certain genes on or off.

In practice, this means a few things happen in a formula. It:

That last two are worth a closer look.

A study that tested Retinol directly (not just prescription Retinoic Acid) found that four weeks of retinol thickened the epidermis and switched on the genes for Collagen I and Collagen III, with more procollagen I and III showing up in the skin. And after twelve weeks, facial wrinkles were visibly reduced.

Retinoids more broadly stimulate the skin's synthesis of hyaluronan and other glycosaminoglycans, part of what gives skin a plumper, more hydrated look over time.

So even the gentler OTC form is doing real structural work (not just sitting on the surface).

It's also worth knowing Retinol isn't only a wrinkle ingredient; it can help with uneven tone, dark spots, rough texture, and the look of pores as well because it speeds up turnover and influences pigment.

The research backs this up as well.

A pooled analysis of six clinical studies found that 0.1% stabilized retinol improved all signs of photoaging versus vehicle as early as week 4 and through 12 weeks, with only a few mild cases of irritation.

Another study comparing concentrations found that 0.3% and 1% Retinol were similarly effective at remodeling photodamaged skin, but 0.3% caused fewer adverse reactions when used daily (a useful reminder that more isn't always better).

Retinol is about tenfold less potent than Retinoic Acid. This is why it works as a gentler, non-prescription option that builds results over time.

Typical concentrations range from 0.1-1%, with 0.1% to 0.3% being a well-supported sweet spot for visible benefits with good tolerability.

One quirk worth mentioning: Retinol is famously unstable.

It's highly sensitive to light and oxygen, and UV exposure breaks it down into a range of degradation products.

Real-world testing bears this out, with retinoid content in some products dropping anywhere from 0% to 80% after six months at room temperature, and even more at higher temperatures.

This is why good formulations lean on opaque, air-tight packaging (think tubes and pumps, not clear jars) and often "encapsulate" the Retinol to shield it.

Signs of oxidation include your product turning yellow or smelling "off". Keeping it somewhere cool and dark, and using it up within a few months of opening helps it stay effective.

The most common side effects are mild and temporary: usually some dryness, redness, or light peeling as your skin adjusts. These tend to settle with consistent and lower-frequency use.

Like all retinoids, Retinol works best with nightly use, a good moisturizer, and daytime sunscreen.

The "ramp up" method works well: start with Retinol once a week to give your skin time to adjust, which keeps irritation low. Slowly add more nights until you reach your goal frequency once your skin feels comfortable.

Retinoids also make your skin more sensitive to the sun in the first few weeks, so wear sunscreen every morning and protect your skin from direct sun while you build up tolerance.

One safety note: topical Retinoids aren't recommended during pregnancy or breastfeeding. Systemic absorption from creams is low but because high oral vitamin A is a known teratogen and topical safety data are limited, most clinicians recommend stopping retinoids when pregnant or trying to conceive.

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!

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. 03Acrylates/C10-30 Alkyl Acrylate Crosspolymer is a synthetic polymer. It is used to thicken, emulsify, and improve the texture of products.
  4. 04As an emulsifier, it helps stabilize oil-in-water emulsions to give products an elegant feel when applied.
  5. 05It can also form a thin protective film on skin. One study found that a formula using this polymer helped slow down how quickly other ingredients (like DEET) were absorbed through skin.
  6. 06A 2024 study of over 1,300 patients confirmed that sensitization to this ingredient is rare. It is also non-mutagenic and has a clean track record.
  7. 07Aminomethyl Propanol is used to adjust the pH of products. It is also used as a base to create other organic compounds. Having a balanced pH is important for protecting your skin.
  8. 08Aminomethyl propanol is safe to use in cosmetics up to 1%. It is soluble in water.
  9. 09Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.
  10. 10What it does:
  11. 11Dimethicone comes in different viscosities:
  12. 12Depending on the viscosity, dimethicone has different properties.
  13. 13Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.
  14. 14This 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.
  15. 15Note: 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.
  16. 16Dimethicone Crosspolymer is a silicone created by modifying dimethicone with hydrocarbon side chains. Due to its large size, it does not penetrate skin. It is considered non-occlusive.
  17. 17Dimethicone Crosspolymer is used to stabilize and thicken products. It also helps give products a silky feel.
  18. 18Dimethiconol is a silicone that resembles the popular dimethicone. Like other silicones, it is an emollient. Emollients create a thin film on skin to prevent moisture from escaping.
  19. 19This ingredient helps to create a silky texture and improve spreadability. Due to its high molecular weight and thickness, it is often combined with cyclopentasiloxane.
  20. 20Disodium EDTA is a chelating agent. It grabs onto and deactivates metal ions that sneak into your products from water, packaging, or air.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side