Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Olay Vitamin C + Peptide 24 Versus The Ordinary Caffeine Solution 5% + EGCG

Olay Vitamin C + Peptide 24 Versus The Ordinary Caffeine Solution 5% + EGCG 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 calming eye moisturizer is

Olay Vitamin C + Peptide 24 Versus The Ordinary Caffeine Solution 5% + EGCG

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 calming eye moisturizer is formulated around Caffeine and Epigallocatechin Gallatyl Glucoside to calm redness 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

Caffeine

Maltodextrin

Propanediol

Epigallocatechin Gallatyl Glucoside

Gallyl Glucoside

Hyaluronic Acid

Oxidized Glutathione

Melanin

Glycine Soja Seed Extract

Pentylene Glycol

Hydroxyethylcellulose

Polyacrylate Crosspolymer-6

Xanthan Gum

Dehydroacetic Acid

Trisodium Ethylenediamine Disuccinate

Propyl Gallate

Dimethyl Isosorbide

Benzyl Alcohol

1,2-Hexanediol

Ethylhexylglycerin

Phenoxyethanol

Caprylyl Glycol

Water, Caffeine, Maltodextrin, Glycerin, Propanediol, Epigallocatechin Gallatyl Glucoside, Gallyl Glucoside, Hyaluronic Acid, Oxidized Glutathione, Melanin, Glycine Soja Seed Extract, Pentylene Glycol, Hydroxyethylcellulose, Polyacrylate Crosspolymer-6, Xanthan Gum, Lactic Acid, Dehydroacetic Acid, Trisodium Ethylenediamine Disuccinate, Propyl Gallate, Dimethyl Isosorbide, Benzyl Alcohol, 1,2-Hexanediol, Ethylhexylglycerin, Phenoxyethanol, Caprylyl Glycol

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.

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.

Lactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.

Its main role is to exfoliate the surface of the skin by loosening the “glue” that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

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. 13Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  14. 14Topically, glycerin does several things at once:
  15. 15Your 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.
  16. 16Aquaporin-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.
  17. 17This 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.
  18. 18Just know very high concentrations (>40%) can feel tacky in low humidity.
  19. 19Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  20. 20Water. 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.
Source · skinsort.com
02

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 →
03

Comparison edit

Read side by side