Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Paula's Choice C15 Super Booster

Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Paula's Choice C15 Super Booster This anti-aging serum is formulated around Niacinamide and Polyglutamic Acid to soften the look of wrinkles and brighten dull-looking skin. This brightening serum

Charlotte Tilbury Charlotte's Magic Serum Crystal Elixir Versus Paula's Choice C15 Super Booster

This anti-aging serum is formulated around Niacinamide and Polyglutamic Acid to soften the look of wrinkles and brighten dull-looking 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

Niacinamide

Glycereth-26

Triheptanoin

Glycerin

Methyl Gluceth-20

Silica

Camellia Oleifera Seed Oil

Quartz Powder

Amethyst Powder

Ruby Powder

Gold

Butyrospermum Parkii Oil

Phenoxyethanol

Dimethyl Isosorbide

Polysorbate 20

Glyceryl Stearate

Butylene Glycol

Octyldodecyl Oleate

Benzyl Alcohol

Myrothamnus Flabellifolia Leaf Extract

PEG-100 Stearate

Octyldodecyl Stearoyl Stearate

Schisandra Chinensis Fruit Extract

Carbomer

Sodium Gluconate

Sodium Hyaluronate

Chondrus Crispus Extract

Sodium Hydroxide

Saussurea Involucrata Callus Extract

Tocopheryl Acetate

Aloe Barbadensis Leaf Juice

Polyglutamic Acid

Pentylene Glycol

Sorbitol

Magnesium Aspartate

Zinc Gluconate

Rosa Canina Fruit Extract

Polyhydroxystearic Acid

Octyldodecanol

Sodium Benzoate

Propanediol

Biosaccharide Gum-4

Xanthan Gum

Parfum

Plumeria Alba Flower Extract

Plumeria Rubra Flower Extract

Lithothamnion Calcareum Extract

Lactic Acid

Potassium Sorbate

Caprylyl Glycol

Copper Gluconate

Hydrated Silica

1,2-Hexanediol

Citric Acid

Solanum Tuberosum Pulp Extract

Acetyl Tetrapeptide-11

Acetyl Tetrapeptide-9

Dehydroacetic Acid

Ascorbic Acid

Glutathione

Limonene

Geraniol

Citronellol

Linalool

Citral

Water, Niacinamide, Glycereth-26, Triheptanoin, Glycerin, Methyl Gluceth-20, Silica, Camellia Oleifera Seed Oil, Quartz Powder, Amethyst Powder, Ruby Powder, Gold, Butyrospermum Parkii Oil, Phenoxyethanol, Dimethyl Isosorbide, Polysorbate 20, Glyceryl Stearate, Butylene Glycol, Octyldodecyl Oleate, Benzyl Alcohol, Myrothamnus Flabellifolia Leaf Extract, PEG-100 Stearate, Octyldodecyl Stearoyl Stearate, Schisandra Chinensis Fruit Extract, Carbomer, Sodium Gluconate, Sodium Hyaluronate, Chondrus Crispus Extract, Sodium Hydroxide, Saussurea Involucrata Callus Extract, Tocopheryl Acetate, Aloe Barbadensis Leaf Juice, Polyglutamic Acid, Pentylene Glycol, Sorbitol, Magnesium Aspartate, Zinc Gluconate, Rosa Canina Fruit Extract, Polyhydroxystearic Acid, Octyldodecanol, Sodium Benzoate, Propanediol, Biosaccharide Gum-4, Xanthan Gum, Parfum, Plumeria Alba Flower Extract, Plumeria Rubra Flower Extract, Lithothamnion Calcareum Extract, Lactic Acid, Potassium Sorbate, Caprylyl Glycol, Copper Gluconate, Hydrated Silica, 1,2-Hexanediol, Citric Acid, Solanum Tuberosum Pulp Extract, Acetyl Tetrapeptide-11, Acetyl Tetrapeptide-9, Dehydroacetic Acid, Ascorbic Acid, Glutathione, Limonene, Geraniol, Citronellol, Linalool, Citral

Dipropylene Glycol

Ethoxydiglycol

PPG-26-Buteth-26

PEG-40 Hydrogenated Castor Oil

Bisabolol

Ferulic Acid

Sodium Phytate

Decylene Glycol

Tocopherol

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

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.

It is a:

Humectant, drawing moisture into the skin

Emollient, helping to soften skin

Solvent, dispersing and stabilizing formulas

Preservative booster, enhancing the antimicrobial activity of other preservatives

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.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.

It’s often used to:

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Side-by-side

  1. 01Aloe Barbadensis Leaf Water
  2. 02Water
  3. 03Butylene Glycol
  4. 04Brassica Oleracea Acephala Leaf Extract
  5. 05Glycolic Acid
  6. 061,2-Hexanediol
  7. 07Potassium Hydroxide
  8. 08Glycerin
  9. 09Spinacia Oleracea Leaf Extract
  10. 10Carum Petroselinum Extract
  11. 11Chlorella Minutissima Extract
  12. 12Malus Domestica Fruit Extract
  13. 13Panthenol
  14. 14Betaine Salicylate
  15. 15Sodium Hyaluronate
  16. 16Allantoin
  17. 17Camellia Sinensis Seed Oil
  18. 18Dipotassium Glycyrrhizate
  19. 19Bacillus/Folic Acid/Soybean Ferment Extract
  20. 20Coptis Japonica Root Extract
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side