Skin science article
The INKEY List 15% Vitamin C And EGF Serum Versus Rodial Pink Diamond Instant lifting Serum
The INKEY List 15% Vitamin C And EGF Serum Versus Rodial Pink Diamond Instant lifting Serum This brightening serum is formulated around Ascorbyl Glucoside to brighten dull-looking skin and fade the look of dark spots. This brightening serum is formulated aroun
The INKEY List 15% Vitamin C And EGF Serum Versus Rodial Pink Diamond Instant lifting Serum
This brightening serum is formulated around Ascorbyl Glucoside to brighten dull-looking skin and fade the look of dark spots.
This brightening serum is formulated around Sodium Ascorbyl Phosphate to brighten dull-looking skin and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Ascorbyl Glucoside
Sodium Hydroxide
PEG-40 Hydrogenated Castor Oil
Phenoxyethanol
Benzyl Alcohol
Butylene Glycol
Xanthan Gum
Ethylhexylglycerin
Sodium Metabisulfite
Dehydroacetic Acid
Phytic Acid
Oligopeptide-1
Water, Ascorbyl Glucoside, Sodium Hydroxide, PEG-40 Hydrogenated Castor Oil, Phenoxyethanol, Benzyl Alcohol, Butylene Glycol, Xanthan Gum, Ethylhexylglycerin, Sodium Metabisulfite, Dehydroacetic Acid, Phytic Acid, Oligopeptide-1
Hdi/Trimethylol Hexyllactone Crosspolymer
Carbomer
Mica
Glycerin
Sodium Ascorbyl Phosphate
Macrocystis Pyrifera Extract
Cyclopentasiloxane
Buteth-3
Hydrolyzed Wheat Protein
Pvp
Sodium Benzotriazolyl Butylphenol Sulfonate
Ethylhexyl Cocoate
Disodium EDTA
Polymethylsilsesquioxane
Parfum
Silica
Dimethiconol
Propylene Glycol
Tributyl Citrate
Dimethylmethoxy Chromanyl Palmitate
Citronellol
Water, Butylene Glycol, Hdi/Trimethylol Hexyllactone Crosspolymer, PEG-40 Hydrogenated Castor Oil, Carbomer, Phenoxyethanol, Benzyl Alcohol, Mica, Glycerin, Sodium Ascorbyl Phosphate, Macrocystis Pyrifera Extract, Sodium Hydroxide, Cyclopentasiloxane, Buteth-3, Hydrolyzed Wheat Protein, Pvp, Sodium Benzotriazolyl Butylphenol Sulfonate, Ethylhexyl Cocoate, Disodium EDTA, Polymethylsilsesquioxane, Parfum, Ethylhexylglycerin, Dehydroacetic Acid, Silica, Dimethiconol, Propylene Glycol, Tributyl Citrate, Dimethylmethoxy Chromanyl Palmitate, Citronellol
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Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Benzyl Alcohol is an aromatic alcohol with several roles: it's a preservative, solvent, and mild fragrance component with a floral scent.
This ingredient has been deemed safe for use in cosmetic formulations at concentrations up to 5%, and up to 10% in hair dyes. You'll typically see 0.5-2% in most rinse-off or leave-on products.
As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.
The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.
This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.
It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.
Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.
At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.
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.
Dehydroacetic Acid is a synthetic preservative that keeps your products safe from microbes.
As an organic acid, it penetrates microbial cell walls and disrupts cellular metabolism. This makes it effective against bacteria, yeast, and mold.
It is effective at low concentrations (<0.6%). Clinical studies have found it to be non-irritating, non-sensitizing, and non-photosensitizing.
Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.
Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
PEG-40 Hydrogenated Castor Oil is an emulsifier derived from castor oil.
As an emulsifying agent, it helps other ingredients like fragrances and fat-soluble vitamins dissolve cohesively.
Due to its large molecule size, it doesn't penetrate beyond the skin's surface.
This ingredient has a solid regulatory track record; the CIR Expert Panel first concluded it was safe for use in cosmetics at concentrations up to 100% in 1997. A 2012 reassessment reaffirmed that finding. Safety studies have also found no irritation or evidence of toxicity.
A 2019 study did find this ingredient to grow Malassezia, so this ingredient may not be fungal acne safe.
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 Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.
In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.
"Alkaline" refers to a high pH level. A low pH level would be considered acidic.
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!