La Roche-Posay Mela B3 Dark Spot Serum With Melasyl+Niacinamide Versus Beauty of Joseon Day Dew Sunscreen SPF 50

La Roche-Posay Mela B3 Dark Spot Serum With Melasyl+Niacinamide Versus Beauty of Joseon Day Dew Sunscreen SPF 50

This brightening serum is formulated around Niacinamide and 2-Mercaptonicotinoyl Glycine to fade the look of dark spots and refine skin texture.

This chemical sunscreen covers most of the UV range, lighter on the deep UVA that drives aging.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Dimethicone

Niacinamide

Glycerin

Propylene Glycol

Polysilicone-11

Silica

Bis-PEG/PPG-16/16 PEG/PPG-16/16 Dimethicone

Cystoseira Tamariscifolia Extract

2-Mercaptonicotinoyl Glycine

PEG-20 Methyl Glucose Sesquistearate

Sodium Hyaluronate

Sodium Hydroxide

Sodium Thiosulfate

Carnosine

Poloxamer 338

Ammonium Polyacryloyldimethyl Taurate

Dipotassium Glycyrrhizate

Caprylic/Capric Triglyceride

Capryloyl Salicylic Acid

Caprylyl Glycol

Citric Acid

Trisodium Ethylenediamine Disuccinate

Xanthan Gum

Pentylene Glycol

Octyldodecanol

Retinyl Palmitate

Tocopherol

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Phenoxyethanol

CI 17200

Parfum

Water, Dimethicone, Niacinamide, Glycerin, Propylene Glycol, Polysilicone-11, Silica, Bis-PEG/PPG-16/16 PEG/PPG-16/16 Dimethicone, Cystoseira Tamariscifolia Extract, 2-Mercaptonicotinoyl Glycine, PEG-20 Methyl Glucose Sesquistearate, Sodium Hyaluronate, Sodium Hydroxide, Sodium Thiosulfate, Carnosine, Poloxamer 338, Ammonium Polyacryloyldimethyl Taurate, Dipotassium Glycyrrhizate, Caprylic/Capric Triglyceride, Capryloyl Salicylic Acid, Caprylyl Glycol, Citric Acid, Trisodium Ethylenediamine Disuccinate, Xanthan Gum, Pentylene Glycol, Octyldodecanol, Retinyl Palmitate, Tocopherol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Phenoxyethanol, CI 17200, Parfum

Butyl Methoxydibenzoylmethane

Homosalate

Ethylhexyl Salicylate

Octocrylene

Butyloctyl Salicylate

Poly C10-30 Alkyl Acrylate

Vp/Eicosene Copolymer

Cetearyl Alcohol

Sodium Stearoyl Glutamate

Hydroxyacetophenone

Tocopheryl Acetate

Panthenol

Propanediol

Oryza Sativa Extract

1,2-Hexanediol

Butyl Methoxydibenzoylmethane, Homosalate, Ethylhexyl Salicylate, Octocrylene, Water, Butyloctyl Salicylate, Glycerin, Dimethicone, Poly C10-30 Alkyl Acrylate, Vp/Eicosene Copolymer, Cetearyl Alcohol, Niacinamide, Sodium Stearoyl Glutamate, Ammonium Polyacryloyldimethyl Taurate, Hydroxyacetophenone, Phenoxyethanol, Tocopheryl Acetate, Panthenol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Xanthan Gum, Propanediol, Oryza Sativa Extract, 1,2-Hexanediol, Sodium Hyaluronate

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.

Ammonium Polyacryloyldimethyl Taurate is a polymer made from ammonium salts. It works as a thickener, emulsifier, and texture enhancer that gives gel-creams a silky, lightweight feel.

This ingredient is versatile and low-maintenance so manufacturers love working with it.

Typical usage levels in cosmetics are usually low and in the range of 0.015 - 2.3%.

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.

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.

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

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.

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.

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