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Skin science article

Obagi Professional-C Serum 20% Versus Murad Vitamin C Glycolic Brightening Serum

Obagi Professional-C Serum 20% Versus Murad Vitamin C Glycolic Brightening Serum This brightening serum is formulated around Ascorbic Acid and Ascorbyl Glucoside to brighten dull-looking skin and soften the look of wrinkles. This brightening serum is formulate

Obagi Professional-C Serum 20% Versus Murad Vitamin C Glycolic Brightening Serum

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

This brightening serum is formulated around Glycolic Acid and Ascorbic Acid to brighten dull-looking skin and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Propylene Glycol

Water

Ascorbic Acid

Alcohol

Ascorbyl Glucoside

Ethoxydiglycol

Phenoxyethanol

Sorbitol

Sodium Hyaluronate

Zinc Chloride

Calcium Hydroxide

Parfum

Propylene Glycol, Water, Ascorbic Acid, Alcohol, Ascorbyl Glucoside, Ethoxydiglycol, Phenoxyethanol, Sorbitol, Sodium Hyaluronate, Zinc Chloride, Calcium Hydroxide, Parfum

Glycolic Acid

Glycerin

Caprylic/Capric Triglyceride

Dimethicone

Sodium Hydroxide

Hdi/Trimethylol Hexyllactone Crosspolymer

Diisopropyl Sebacate

C13-16 Isoparaffin

Polyacrylate Crosspolymer-6

Dimethyl Isosorbide

Urea

Yeast Amino Acids

Trehalose

Inositol

Taurine

Betaine

Glutathione

Tetrahexyldecyl Ascorbate

Cetearyl Isononanoate

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Oleyl Alcohol

Silica

Hexylresorcinol

Polysilicone-11

Triheptanoin

Polyisobutene

Marrubium Vulgare Meristem Cell Culture

Zanthoxylum Bungeanum Fruit Extract

Hydrolyzed Verbascum Thapsus Flower

Butylene Glycol

Mica

Hexylene Glycol

Sodium Surfactin

Xymenynic Acid

Tocopheryl Acetate

PEG-7 Trimethylolpropane Coconut Ether

Terminalia Ferdinandiana Fruit Extract

Tin Oxide

Xanthan Gum

T-Butyl Alcohol

Chlorella Vulgaris Extract

Decyl Glucoside

Gold

Citric Acid

Caprylyl Glycol

Ethylhexylglycerin

Sodium Benzoate

Potassium Sorbate

CI 77891

Water, Glycolic Acid, Glycerin, Caprylic/Capric Triglyceride, Dimethicone, Sodium Hydroxide, Hdi/Trimethylol Hexyllactone Crosspolymer, Diisopropyl Sebacate, C13-16 Isoparaffin, Polyacrylate Crosspolymer-6, Dimethyl Isosorbide, Ascorbic Acid, Urea, Yeast Amino Acids, Trehalose, Inositol, Taurine, Betaine, Glutathione, Tetrahexyldecyl Ascorbate, Cetearyl Isononanoate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Oleyl Alcohol, Silica, Hexylresorcinol, Polysilicone-11, Triheptanoin, Polyisobutene, Marrubium Vulgare Meristem Cell Culture, Zanthoxylum Bungeanum Fruit Extract, Hydrolyzed Verbascum Thapsus Flower, Butylene Glycol, Mica, Hexylene Glycol, Sodium Surfactin, Xymenynic Acid, Tocopheryl Acetate, PEG-7 Trimethylolpropane Coconut Ether, Terminalia Ferdinandiana Fruit Extract, Sorbitol, Tin Oxide, Xanthan Gum, T-Butyl Alcohol, Chlorella Vulgaris Extract, Decyl Glucoside, Gold, Citric Acid, Caprylyl Glycol, Phenoxyethanol, Ethylhexylglycerin, Sodium Benzoate, Potassium Sorbate, CI 77891

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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.

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.

Sorbitol is a sugar alcohol. It is a hydrating and moisturizing agent created from the reduction process of glucose.

Most sorbitol is usually made from potato starch. It is also found in fruits such as apples and pears.

As a humectant, Sorbitol helps draw water to the skin. This helps keep the skin hydrated. Sorbitol also helps create a thicker texture in products. You might find sorbitol in your toothpaste and other gels.

It is a non-irritating ingredient that is great for those with dry skin.

Sorbitol is a prebiotic. It helps promote the growth of healthy bacteria on your skin. The bacteria on your skin form a microbiome. This microbiome helps protect your skin from infection and harmful bacteria.

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 Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin.
  4. 04Not 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:
  5. 05Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently.
  6. 06One 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.
  7. 07While 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.
  8. 08The 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% be…
  9. 09Skin 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.
  10. 10Ascorbic 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…
  11. 11Read more about other types of Vitamin C:
  12. 12Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.
  13. 13Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
  14. 14It 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.
  15. 15On 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.
  16. 16Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
  17. 17You'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.
  18. 18Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
  19. 19Safety-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.
  20. 20Adverse 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.
Source · skinsort.com
02

Product index

Related product references

Product

Obagi Professional-C Serum 20%

Obagi Professional-C Serum 20% Ingredients in Obagi Professional-C Serum 20% explained: benefits, concerns, and detailed analysis of 12 ingredients including Propylene Glycol, Water, and As…

Source: skinsort.comView reference →
03

Comparison edit

Read side by side