Anua Nano Retinol 0.3% + Niacin Renewing Serum Versus Kiehl's Micro-Dose Anti-Aging Retinol Serum with Ceramides and Peptide

Anua Nano Retinol 0.3% + Niacin Renewing Serum Versus Kiehl's Micro-Dose Anti-Aging Retinol Serum with Ceramides and Peptide

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

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

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycereth-26

Niacinamide 5%

Pyrus Malus Fruit Extract

Glycerin

1,2-Hexanediol

Caprylic/Capric Triglyceride

Castanea Crenata Shell Extract

Glyceryl Citrate/Lactate/Linoleate/Oleate

Diospyros Kaki Leaf Extract

Coptis Japonica Root Extract

Potentilla Anserina Extract

Avena Sativa Kernel Extract

Cynara Scolymus Leaf Extract

Portulaca Oleracea Extract

Melaleuca Alternifolia Leaf Extract

Ficus Carica Fruit Extract

Centella Asiatica Extract

Camellia Sinensis Leaf Extract

Artemisia Capillaris Flower Extract

Arnica Montana Flower Extract

Houttuynia Cordata Extract

Melia Azadirachta Leaf Extract

Lavandula Angustifolia Flower Extract

Chamomilla Recutita Flower/Leaf Extract

Borago Officinalis Extract

Centaurea Cyanus Flower Extract

Hydrogenated Lecithin

Camellia Sinensis Leaf Water

Centaurea Cyanus Flower Water

Sodium Hyaluronate

Melaleuca Alternifolia Leaf Oil

Carapa Guaianensis Seed Oil

Hippophae Rhamnoides Acid

Tocopherol

Cetyl Ethylhexanoate

Ammonium Acryloyldimethyltaurate/Vp Copolymer

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Polyacrylate Crosspolymer-6

Methylpropanediol

Butylene Glycol

Polysorbate 20

Retinol 0.1%

Ceramide NP

Pentylene Glycol

Carbomer

Tromethamine

Dipotassium Glycyrrhizate

Ethylhexylglycerin

Adenosine

Disodium EDTA

Polyquaternium-51

Squalane

Panthenol

Hydrolyzed Sodium Hyaluronate

BHT

Oleic Acid

Dipropylene Glycol

BHA

Allantoin

Maltodextrin

Saccharide Hydrolysate

Sorbitan Laurate

Glyceryl Stearate

Butyrospermum Parkii Butter

Octyldodecanol

Phytosterols

Madecassoside

Ceramide As

Ceramide AP

Capryloyl Salicylic Acid

Cholesterol

Hydroxyethylcellulose

Acetyl Dipeptide-1 Cetyl Ester

Ceramide Ns

Ceramide Ng

Caprylyl Glycol

Guaiazulene

Sucrose Distearate

Nonapeptide-1

Acetyl Hexapeptide-8

Copper Tripeptide-1

Tripeptide-1

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Palmitoyl Pentapeptide-4

Hydroxypropyl Cyclodextrin

Hexapeptide-9

Ceramide EOP

Water, Glycereth-26, Niacinamide 5%, Pyrus Malus Fruit Extract, Glycerin, 1,2-Hexanediol, Caprylic/Capric Triglyceride, Castanea Crenata Shell Extract, Glyceryl Citrate/Lactate/Linoleate/Oleate, Diospyros Kaki Leaf Extract, Coptis Japonica Root Extract, Potentilla Anserina Extract, Avena Sativa Kernel Extract, Cynara Scolymus Leaf Extract, Portulaca Oleracea Extract, Melaleuca Alternifolia Leaf Extract, Ficus Carica Fruit Extract, Centella Asiatica Extract, Camellia Sinensis Leaf Extract, Artemisia Capillaris Flower Extract, Arnica Montana Flower Extract, Houttuynia Cordata Extract, Melia Azadirachta Leaf Extract, Lavandula Angustifolia Flower Extract, Chamomilla Recutita Flower/Leaf Extract, Borago Officinalis Extract, Centaurea Cyanus Flower Extract, Hydrogenated Lecithin, Camellia Sinensis Leaf Water, Centaurea Cyanus Flower Water, Sodium Hyaluronate, Melaleuca Alternifolia Leaf Oil, Carapa Guaianensis Seed Oil, Hippophae Rhamnoides Acid, Tocopherol, Cetyl Ethylhexanoate, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Polyacrylate Crosspolymer-6, Methylpropanediol, Butylene Glycol, Polysorbate 20, Retinol 0.1%, Ceramide NP, Pentylene Glycol, Carbomer, Tromethamine, Dipotassium Glycyrrhizate, Ethylhexylglycerin, Adenosine, Disodium EDTA, Polyquaternium-51, Squalane, Panthenol, Hydrolyzed Sodium Hyaluronate, BHT, Oleic Acid, Dipropylene Glycol, BHA, Allantoin, Maltodextrin, Saccharide Hydrolysate, Sorbitan Laurate, Glyceryl Stearate, Butyrospermum Parkii Butter, Octyldodecanol, Phytosterols, Madecassoside, Ceramide As, Ceramide AP, Capryloyl Salicylic Acid, Cholesterol, Hydroxyethylcellulose, Acetyl Dipeptide-1 Cetyl Ester, Ceramide Ns, Ceramide Ng, Caprylyl Glycol, Guaiazulene, Sucrose Distearate, Nonapeptide-1, Acetyl Hexapeptide-8, Copper Tripeptide-1, Tripeptide-1, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1, Palmitoyl Pentapeptide-4, Hydroxypropyl Cyclodextrin, Hexapeptide-9, Ceramide EOP

Niacinamide

Cetyl Alcohol

Isohexadecane

Isononyl Isononanoate

Diisopropyl Sebacate

2-Oleamido-1,3-Octadecanediol

4-T-Butylcyclohexanol

Hydroxypalmitoyl Sphinganine

Lauroyl Lysine

Sodium Chloride

Sodium Hydroxide

Trisodium Ethylenediamine Disuccinate

Retinol

Dicaprylyl Ether

Ammonium Polyacryloyldimethyl Taurate

Behenyl Alcohol

Cetearyl Alcohol

Cetearyl Glucoside

Glycine Soja Oil

Helianthus Annuus Seed Oil

Lecithin

Phenethyl Alcohol

Poloxamer 188

Polycaprolactone

Steareth-100

CI 40800

Chlorphenesin

Phenoxyethanol

Water, Glycerin, Butylene Glycol, Pentylene Glycol, Niacinamide, Cetyl Alcohol, Isohexadecane, Isononyl Isononanoate, Diisopropyl Sebacate, 2-Oleamido-1,3-Octadecanediol, 4-T-Butylcyclohexanol, Acetyl Dipeptide-1 Cetyl Ester, Adenosine, Ceramide NP, Hydroxypalmitoyl Sphinganine, Lauroyl Lysine, Octyldodecanol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Sodium Chloride, Sodium Hyaluronate, Sodium Hydroxide, Trisodium Ethylenediamine Disuccinate, Retinol, Tocopherol, Dicaprylyl Ether, Ammonium Polyacryloyldimethyl Taurate, Behenyl Alcohol, Caprylyl Glycol, Carbomer, Cetearyl Alcohol, Cetearyl Glucoside, Glycine Soja Oil, Helianthus Annuus Seed Oil, Hydroxyethylcellulose, Lecithin, Phenethyl Alcohol, Poloxamer 188, Polycaprolactone, Sorbitan Laurate, Steareth-100, CI 40800, Chlorphenesin, Phenoxyethanol

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.

Acetyl Dipeptide-1 Cetyl Ester is a peptide composed of amino acids arginine and tyrosine.

This peptide is considered a neurotransmitter peptide, meaning it has pain-relieving and relaxing properties. It has the ability to calm skin irritation from external factors such as chemical stinging or heat.

Neurotransmitter peptides are also often called "botox in a bottle". This is because these peptides have the ability to relax the muscles.

Though relaxing the muscles can prevent expression lines (as we have seen in botox), the studies do not show these peptides to be a botox replacement. The effects of this muscle relaxation is also short-term, as opposed to longer-term results from botox.

Adenosine is a purine nucleoside that your body already makes in every cell. In skincare, it acts mainly as a skin conditioning and anti-aging agent.

The way it works is fairly well mapped out:

Your skin has cells called fibroblasts that build collagen (the stuff that keeps skin firm and smooth). Adenosine basically flips a switch on these cells that tells them to get to work making more collagen and other proteins. These cells slow down on their own as skin ages, so Adenosine helps give them a little nudge to keep going.

The clinical backing is pretty solid too.

A blind, randomized, placebo-controlled trial of 126 women aged 45-65 tested a 0.1% cream twice daily and found real improvements in crow's feet and frown lines using a precise 3D skin-mapping technique; these changes showed up by week 3 and held at 2 months.

A later study using Adenosine-loaded dissolving microneedle patches reported gains in wrinkle depth, dermal density, elasticity, and hydration.

On concentrations, South Korea's Ministry of Food and Drug Safety has set 0.04% as the approved functional anti-wrinkle level. You'll typically see this ingredient used somewhere in the 0.04-0.1% range since it works at low doses.

This ingredient has been found safe for cosmetics with the data showing no irritation or sensitization.

Overall, this is a great ingredient for any anti-aging routine and has no photosensitizing effect, so it suits both AM and PM use.

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

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.

Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.

It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.

Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.

A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.

Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.

Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.

This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

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.

Hydroxyethylcellulose is used to improve the texture of products. It is created from a chemical reaction involving ethylene oxide and alkali-cellulose. Cellulose is a sugar found in plant cell walls and help give plants structure.

This ingredient helps stabilize products by preventing ingredients from separating. It can also help thicken the texture of a product.

This ingredient can also be found in pill medicines to help our bodies digest other ingredients.

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.

Octyldodecanol is a fatty alcohol sourced from plant oils like coconut or palm (or made synthetically).

It is:

You'll likely see this in many BHA products because this is the go-to solvent for salicylic acid.

This ingredient is typically used at levels between 2-20%.

Regarding fungal acne: In 2019, this ingredient was tested against multiple Malassezia species (the yeast that causes fungal acne) and showed no growth.

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate (long name, huh?) is a synthetic antioxidant.

It is used to help stabilize other antioxidants or prevent the color from changing in a product.

As an antioxidant, it helps fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material. Thus, antioxidants may reduce the signs of aging.

This ingredient is oil-soluble.

Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:

Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

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.

Sodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.

In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

Sorbitan Laurate is created from lauric acid and derivatives from sorbitol. It is an emulsifier.

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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!

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