Skin science article
Glow Recipe Guava Vitamin C Dark Spot Treatment Serum Versus Paula's Choice Skin Recovery Replenishing Moisturizer
Glow Recipe Guava Vitamin C Dark Spot Treatment Serum Versus Paula's Choice Skin Recovery Replenishing Moisturizer This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Tranexamic Acid to fade the look of dark spots and brighten dull-lookin
Glow Recipe Guava Vitamin C Dark Spot Treatment Serum Versus Paula's Choice Skin Recovery Replenishing Moisturizer
This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin.
This barrier-repair moisturizer is formulated around Oenothera Biennis Oil and Panthenol to strengthen the skin barrier and hydrate skin.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Propanediol
C9-12 Alkane
Psidium Guajava Fruit Extract
Tetrahexyldecyl Ascorbate
Tranexamic Acid
Sodium Polyacryloyldimethyl Taurate
3-O-Ethyl Ascorbic Acid
Ascorbyl Glucoside
Magnesium Ascorbyl Phosphate
Sodium Ascorbyl Phosphate
Psidium Guajava Seed Oil
Tocopherol
Tocopheryl Acetate
Sodium Hyaluronate
Ferulic Acid
Tremella Fuciformis Sporocarp Extract
Pyrus Malus Fruit Extract
Musa Sapientum Fruit Extract
Prunus Armeniaca Kernel Extract
Pyrus Communis Fruit Extract
Rubus Idaeus Fruit Extract
Melia Azadirachta Flower Extract
Melia Azadirachta Leaf Extract
Corallina Officinalis Extract
Coccinia Indica Fruit Extract
Hexanoyl Dipeptide-3 Norleucine Acetate
Polyglyceryl-10 Dioleate
Glycerin
1,2-Hexanediol
Caprylic/Capric Triglyceride
Caprylyl Glycol
Hydroxyacetophenone
Sodium Stearoyl Glutamate
Coco-Caprylate/Caprate
Betaine
Lecithin
Polyglyceryl-10 Dipalmitate
Sodium Citrate
Sodium Phytate
Potassium Sorbate
Decyl Glucoside
Lauryl Glucoside
Ethylhexylglycerin
Citric Acid
Xanthan Gum
Phenoxyethanol
Water, Propanediol, C9-12 Alkane, Psidium Guajava Fruit Extract, Tetrahexyldecyl Ascorbate, Tranexamic Acid, Sodium Polyacryloyldimethyl Taurate, 3-O-Ethyl Ascorbic Acid, Ascorbyl Glucoside, Magnesium Ascorbyl Phosphate, Sodium Ascorbyl Phosphate, Psidium Guajava Seed Oil, Tocopherol, Tocopheryl Acetate, Sodium Hyaluronate, Ferulic Acid, Tremella Fuciformis Sporocarp Extract, Pyrus Malus Fruit Extract, Musa Sapientum Fruit Extract, Prunus Armeniaca Kernel Extract, Pyrus Communis Fruit Extract, Rubus Idaeus Fruit Extract, Melia Azadirachta Flower Extract, Melia Azadirachta Leaf Extract, Corallina Officinalis Extract, Coccinia Indica Fruit Extract, Hexanoyl Dipeptide-3 Norleucine Acetate, Polyglyceryl-10 Dioleate, Glycerin, 1,2-Hexanediol, Caprylic/Capric Triglyceride, Caprylyl Glycol, Hydroxyacetophenone, Sodium Stearoyl Glutamate, Coco-Caprylate/Caprate, Betaine, Lecithin, Polyglyceryl-10 Dipalmitate, Sodium Citrate, Sodium Phytate, Potassium Sorbate, Decyl Glucoside, Lauryl Glucoside, Ethylhexylglycerin, Citric Acid, Xanthan Gum, Phenoxyethanol
Cetearyl Ethylhexanoate
Butylene Glycol
Glycereth-26
Oenothera Biennis Oil
Cetyl Alcohol
Neopentyl Glycol Diheptanoate
Cyclopentasiloxane
Stearic Acid
Glyceryl Stearate
PEG-100 Stearate
Cyclohexasiloxane
Dimethicone
Panthenol
Palmitoyl Tripeptide-1
Palmitoyl Tetrapeptide-7
Tocopheryl Linoleate
Ascorbyl Palmitate
Dipotassium Glycyrrhizate
Sodium PCA
Anthemis Nobilis Flower Extract
Aloe Barbadensis Leaf Juice
Linoleic Acid
Linolenic Acid
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
Saccharide Isomerate
Hydroxypropyl Guar
Allantoin
Rosa Moschata Seed Oil
Polysorbate 20
Cetyl Hydroxyethylcellulose
Carbomer
Trisodium EDTA
Batyl Alcohol
Sodium Hydroxide
Chlorphenesin
Benzoic Acid
Sorbic Acid
Water, Cetearyl Ethylhexanoate, Butylene Glycol, Glycereth-26, Oenothera Biennis Oil, Cetyl Alcohol, Neopentyl Glycol Diheptanoate, Cyclopentasiloxane, Stearic Acid, Glyceryl Stearate, PEG-100 Stearate, Glycerin, Cyclohexasiloxane, Dimethicone, Panthenol, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Sodium Hyaluronate, Tocopheryl Linoleate, Tocopheryl Acetate, Tocopherol, Magnesium Ascorbyl Phosphate, Ascorbyl Palmitate, Dipotassium Glycyrrhizate, Sodium PCA, Anthemis Nobilis Flower Extract, Aloe Barbadensis Leaf Juice, Sodium Ascorbyl Phosphate, Linoleic Acid, Linolenic Acid, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Saccharide Isomerate, Hydroxypropyl Guar, Allantoin, Rosa Moschata Seed Oil, Polysorbate 20, Cetyl Hydroxyethylcellulose, Carbomer, Sodium Citrate, Trisodium EDTA, Batyl Alcohol, Sodium Hydroxide, Phenoxyethanol, Chlorphenesin, Benzoic Acid, Sorbic Acid
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.
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.
Magnesium Ascorbyl Phosphate (MAP) is a water-soluble form of Vitamin C. It is used in skincare because it tends to be more formulation friendly than pure vitamin C (ascorbic acid).
According to research, MAP has three major benefits:
While MAP is gentler on the skin than ascorbic acid, it is thought to be less easily absorbed into the skin.
In a well-known absorption study, pure vitamin C increased skin vitamin C levels when formulated correctly, but derivatives like MAP did not in that experiment. This suggests MAP may not always convert into active vitamin C in the skin.
Due to MAP's stability up to a pH level of 7, it is more stable to air and sunlight exposure than ascorbic acid. The best pH range for MAP is between 5 and 6.
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 Ascorbyl Phosphate (SAP) is a water-soluble form of Vitamin C. It is the salt of ascorbic acid.
This ingredient is commonly used in skincare because it's more formulation-stable while still offering the same benefits as pure ascorbic acid. Ascorbic acid is notorious for breaking down when exposed to sunlight and oxygen whereas SAP has been shown to be more stable.
Studies show SAP has anti-acne and antioxidant benefits. One study found 5% of SAP lotion to be an effective ingredient for treating acne vulgaris. This is because research shows that SAP may help control acne by reducing acne-causing bacteria and slowing the oxidation of skin oils caused by UV exposure.
In addition to acne, vitamin C is important for skin structure. Lab studies suggest SAP may support collagen production in skin cells, making it a great ingredient in anti-aging routines.
Vitamin C has many benefits: it helps reduce redness, improve skin texture, fade the appearance of dark spots, and brighten the skin.
Read more about other types of Vitamin C:
Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.
Its main functions are to maintain the pH of a product and neutralize metal ions.
The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).
Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.
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.
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.
Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.
Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.
Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.
The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.
Most leave-on skincare keeps it at the lower end, often between 0.5-1%.
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!