Paula's Choice C15 Super Booster Versus Drunk Elephant C-Firma Fresh Day Serum

Paula's Choice C15 Super Booster Versus Drunk Elephant C-Firma Fresh Day Serum

This brightening serum is formulated around Ascorbic Acid and Tocopherol to brighten dull-looking skin and soften the look of wrinkles.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Ascorbic Acid

Butylene Glycol

Ethoxydiglycol

Glycerin

PPG-26-Buteth-26

PEG-40 Hydrogenated Castor Oil

Pentylene Glycol

Tocopherol

Hexanoyl Dipeptide-3 Norleucine Acetate

Lecithin

Ferulic Acid

Panthenol

Bisabolol

Oryza Sativa Bran Extract

Propyl Gallate

Sodium Gluconate

Sodium Hydroxide

Phenoxyethanol

Ethylhexylglycerin

Water, Ascorbic Acid, Butylene Glycol, Ethoxydiglycol, Glycerin, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Pentylene Glycol, Tocopherol, Hexanoyl Dipeptide-3 Norleucine Acetate, Lecithin, Ferulic Acid, Panthenol, Bisabolol, Oryza Sativa Bran Extract, Propyl Gallate, Sodium Gluconate, Sodium Hydroxide, Phenoxyethanol, Ethylhexylglycerin

Dimethyl Isosorbide

Laureth-23

Lactobacillus/Pumpkin Ferment Extract

Sclerocarya Birrea Seed Oil

Dipotassium Glycyrrhizate

Glycyrrhiza Glabra Root Extract

Vitis Vinifera Juice Extract

Phyllanthus Emblica Fruit Extract

Camellia Sinensis Leaf Extract

Lactobacillus/Punica Granatum Fruit Ferment Extract

Propanediol

Gluconolactone

Sodium Hyaluronate Crosspolymer

Sodium Hyaluronate

Glutamylamidoethyl Imidazole

Tetrahydrobisdemethoxydiferuloylmethane

Tetrahydrodemethoxydiferuloylmethane

Tetrahydrodiferuloylmethane

Caprylhydroxamic Acid

Leuconostoc/Radish Root Ferment Filtrate

Sorbic Acid

Sodium Benzoate

Caprylyl Glycol

Chondrus Crispus Extract

Water, Dimethyl Isosorbide, Ascorbic Acid, Laureth-23, Glycerin, Tocopherol, Lactobacillus/Pumpkin Ferment Extract, Sclerocarya Birrea Seed Oil, Dipotassium Glycyrrhizate, Glycyrrhiza Glabra Root Extract, Vitis Vinifera Juice Extract, Ferulic Acid, Phyllanthus Emblica Fruit Extract, Camellia Sinensis Leaf Extract, Lactobacillus/Punica Granatum Fruit Ferment Extract, Propanediol, Gluconolactone, Sodium Hyaluronate Crosspolymer, Sodium Hyaluronate, Oryza Sativa Bran Extract, Glutamylamidoethyl Imidazole, Tetrahydrobisdemethoxydiferuloylmethane, Tetrahydrodemethoxydiferuloylmethane, Tetrahydrodiferuloylmethane, Pentylene Glycol, Caprylhydroxamic Acid, Leuconostoc/Radish Root Ferment Filtrate, Sorbic Acid, Phenoxyethanol, Sodium Benzoate, Caprylyl Glycol, Chondrus Crispus Extract, Ethylhexylglycerin

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.

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.

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.

Ferulic Acid is a plant based antioxidant that can be naturally found in the cell walls of grains like rice, oats, and corn. It has antioxidant and antimicrobial properties, and has the ability to boost the performance of other antioxidants as well.

A well-known study found that adding Ferulic Acid to a solution of Vitamins C and E doubled the photoprotection of skin. This is why you'll often see it paired with Vitamin C or Vitamin E serums rather than sold on its own.

A 2025 review of 18 human studies found that using Ferulic Acid (0.5-1%) daily for one to three months showed improvements in:

As far as allergies go, Ferulic acid is generally well-tolerated but can cause an allergic reaction in very rare cases. It's also worth noting that Ferulic acid is often extracted from plant sources like rice bran or wheat bran, so be sure to path test if you have known grain allergies.

Outside of skincare, researchers are also looking into Ferulic Acid for its potential benefits in areas like diabetes, Alzheimer's, and heart health.

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.

Oryza Sativa Bran Extract comes from the outer layer of a rice kernel. It is a byproduct of milling rice, or the operation to produce a whole grain rice product.

This ingredient has moisturizing properties due to its components of polysaccharides and omega-3 fatty acids. It also contains calcium, selenium, phosphorus, iron, and zinc.

Oryza Sativa Bran Extract contains numerous antioxidants such as ferulic acid. Antioxidants help fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material.

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%.

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.

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!

Similar Comparisons