Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Olay Vitamin C + Peptide 24 Versus Vichy Liftactiv Vitamin C Serum

Olay Vitamin C + Peptide 24 Versus Vichy Liftactiv Vitamin C Serum This brightening moisturizer is formulated around Niacinamide and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and soften the look of wrinkles. This brightening serum is formulated aro

Olay Vitamin C + Peptide 24 Versus Vichy Liftactiv Vitamin C Serum

This brightening moisturizer is formulated around Niacinamide and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and soften the look of wrinkles.

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

Glycerin

Isohexadecane

Niacinamide

Dimethicone

Lactic Acid

Isopropyl Isostearate

Sodium Polyacryloyldimethyl Taurate

Stearyl Alcohol

3-O-Ethyl Ascorbic Acid

Palmitoyl Pentapeptide-4

Panthenol

Sodium Lactate

Trehalose

Cetearyl Glucoside

Cetearyl Alcohol

Behenyl Alcohol

Cetyl Alcohol

Stearic Acid

Palmitic Acid

Dimethiconol

PEG-100 Stearate

Sodium Benzoate

Parfum

Ascorbic Acid

Avena Sativa Peptide

Water, Glycerin, Isohexadecane, Niacinamide, Dimethicone, Lactic Acid, Isopropyl Isostearate, Sodium Polyacryloyldimethyl Taurate, Stearyl Alcohol, 3-O-Ethyl Ascorbic Acid, Palmitoyl Pentapeptide-4, Panthenol, Sodium Lactate, Trehalose, Cetearyl Glucoside, Cetearyl Alcohol, Behenyl Alcohol, Cetyl Alcohol, Stearic Acid, Palmitic Acid, Dimethiconol, PEG-100 Stearate, Sodium Benzoate, Parfum, Ascorbic Acid, Avena Sativa Peptide

Alcohol Denat.

Dipropylene Glycol

Laureth-23

Neohesperidin Dihydrochalcone

Sodium Hydroxide

Tocopherol

Hydrolyzed Hyaluronic Acid

Pinus Pinaster Bark/Bud Extract

Water, Ascorbic Acid, Alcohol Denat., Dipropylene Glycol, Glycerin, Laureth-23, Neohesperidin Dihydrochalcone, Sodium Hydroxide, Tocopherol, Hydrolyzed Hyaluronic Acid, Pinus Pinaster Bark/Bud Extract

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.

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.

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.

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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. 033-O-Ethyl Ascorbic Acid is one of the most popular "stable" vitamin C derivatives in skincare.
  4. 04Plain ascorbic acid is fantastic but notoriously fragile; it browns, oxidizes, and loses potency fast. So attaching an ethyl group to the third carbon of the molecule gives it some cool perks:
  5. 05In a formula, it does the 3 classic vitamin C jobs: it acts as an antioxidant, helps brighten skin tone by inhibiting tyrosinase, and supports collagen.
  6. 06The evidence is reasonably solid for a cosmetic ingredient; Liao and colleagues (2018) showed it's significantly more stable than ascorbic acid while still being effective.
  7. 07A 2021 study by Zerbinati and colleagues tested a serum with 30% 3-O-ethyl-l-ascorbic acid and 1% lactic acid significantly increased collagen production, reduced UVB-induced DNA damage, and decreased melanin on a reconstructed pigmented skin model.
  8. 08Typical real world usage sits around 0.5-5% (and 1-2% is common for daily serums).
  9. 09Amounts up to 30% have been shown to be non-irritating on human skin samples, but two isolated cases reported allergic contact dermatitis so a patch test is sensible if you have reactive skin.
  10. 10Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.
  11. 11What it does:
  12. 12Dimethicone comes in different viscosities:
  13. 13Depending on the viscosity, dimethicone has different properties.
  14. 14Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.
  15. 15This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.
  16. 16Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.
  17. 17Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  18. 18Topically, glycerin does several things at once:
  19. 19Your 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.
  20. 20Aquaporin-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.
Source · skinsort.com
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Product index

Related product references

Product

Olay Vitamin C + Peptide 24

Olay Vitamin C + Peptide 24 Ingredients in Olay Vitamin C + Peptide 24 explained: benefits, concerns, and detailed analysis of 26 ingredients including Water, Glycerin, and Isohexadecane A …

Source: skinsort.comView reference →
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Comparison edit

Read side by side