Skin science article
Dr. Barbara Sturm Glow Drops Versus Paula's Choice C15 Super Booster
Dr. Barbara Sturm Glow Drops Versus Paula's Choice C15 Super Booster This hydrating serum is formulated around Prunus Amygdalus Dulcis Oil to hydrate skin. This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin
Dr. Barbara Sturm Glow Drops Versus Paula's Choice C15 Super Booster
This hydrating serum is formulated around Prunus Amygdalus Dulcis Oil to hydrate skin.
This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Prunus Amygdalus Dulcis Oil
C12-15 Alkyl Benzoate
Glycerin
Lactobacillus/Portulaca Oleracea Ferment Extract
Butylene Glycol
Glyceryl Stearate
Panthenol
Sodium Hyaluronate
Polygonum Bistorta Root Extract
Leuconostoc/Radish Root Ferment Filtrate
Biosaccharide Gum-1
Rosa Canina Fruit Extract
Cetearyl Alcohol
Stearic Acid
Carbomer
Sodium Lauroyl Glutamate
Ethylhexylglycerin
Mica
Hexylene Glycol
Sodium Hydroxide
Alcohol
Caprylic/Capric Triglyceride
Synthetic Fluorphlogopite
Pantolactone
Xanthan Gum
Ascorbyl Palmitate
Citric Acid
Ascorbic Acid
Dimethicone
Phenoxyethanol
Alumina
Tin Oxide
CI 77491
CI 77891
Water, Prunus Amygdalus Dulcis Oil, C12-15 Alkyl Benzoate, Glycerin, Lactobacillus/Portulaca Oleracea Ferment Extract, Butylene Glycol, Glyceryl Stearate, Panthenol, Sodium Hyaluronate, Polygonum Bistorta Root Extract, Leuconostoc/Radish Root Ferment Filtrate, Biosaccharide Gum-1, Rosa Canina Fruit Extract, Cetearyl Alcohol, Stearic Acid, Carbomer, Sodium Lauroyl Glutamate, Ethylhexylglycerin, Mica, Hexylene Glycol, Sodium Hydroxide, Alcohol, Caprylic/Capric Triglyceride, Synthetic Fluorphlogopite, Pantolactone, Xanthan Gum, Ascorbyl Palmitate, Citric Acid, Ascorbic Acid, Dimethicone, Phenoxyethanol, Alumina, Tin Oxide, CI 77491, CI 77891
Dipropylene Glycol
Propanediol
Ethoxydiglycol
PPG-26-Buteth-26
PEG-40 Hydrogenated Castor Oil
Bisabolol
Ferulic Acid
Sodium Phytate
Decylene Glycol
Tocopherol
1,2-Hexanediol
Sphingomonas Ferment Extract
Water, Ascorbic Acid, Dipropylene Glycol, Propanediol, Glycerin, Ethoxydiglycol, Sodium Hydroxide, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Bisabolol, Ferulic Acid, Sodium Phytate, Decylene Glycol, Tocopherol, 1,2-Hexanediol, Sphingomonas Ferment Extract, Phenoxyethanol
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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.
Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin.
Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for:
Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently.
One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin.
While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects.
The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption.
Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits.
Ascorbic acid generally works well with many skincare ingredients but can be irritating when combined with other active ingredients. Strong oxidizing acne treatments like benzoyl peroxide can reduce the effectiveness of vitamin C if they are used at the same time; they are often recommended for use at different times of day.
Read more about other types of Vitamin C:
Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.
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.
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!