Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Dr. Loretta Intense Brightening Cream Versus Paula's Choice C25 Super Booster

Dr. Loretta Intense Brightening Cream Versus Paula's Choice C25 Super Booster This brightening treatment is formulated around Ascorbic Acid to brighten dull-looking skin and fade the look of dark spots. This brightening treatment is formulated around Ascorbic

By Peptide Skincare & Beauty Editorial TeamPublished

Dr. Loretta Intense Brightening Cream Versus Paula's Choice C25 Super Booster

This brightening treatment is formulated around Ascorbic Acid to brighten dull-looking skin and fade the look of dark spots.

This brightening treatment is formulated around Ascorbic Acid to fade the look of dark spots and brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Cyclopentasiloxane

Ascorbic Acid

Polysilicone-11

Ethylhexyl Hydroxystearate

Citrus Aurantium Dulcis Oil

Cyclopentasiloxane, Ascorbic Acid, Polysilicone-11, Ethylhexyl Hydroxystearate, Citrus Aurantium Dulcis Oil

Dimethicone

Polymethylsilsesquioxane

Disteardimonium Hectorite

Propylene Carbonate

Cyclopentasiloxane, Ascorbic Acid, Ethylhexyl Hydroxystearate, Polysilicone-11, Dimethicone, Polymethylsilsesquioxane, Disteardimonium Hectorite, Propylene Carbonate

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.

Cyclopentasiloxane (D5) is a lightweight silicone that mostly acts as an emollient and solvent in cosmetics. Its the reason your products feel silky, fast-spreading, and non-greasy.

Since D5 is volatile, it does its thing and then evaporates off the skin quickly.

The safety profile of this ingredient is reassuring; the US CIR Expert Panel concluded D5 is safe as used in cosmetics and Health Canada concluded that D5 is not harmful to human health or the environment as currently used in cosmetics

There's a study that people mention about D5 in a rat study showing tumors. This study is related to long-term inhalation of high D5 levels.

Regulatory bodies have judged this study to be not applicable in topical skincare since skin absorption of D5 is very low and we're not really inhaling huge amounts of D5.

The only restriction for this ingredient is environmental. The European Chemicals Agency (ECHA) restricted D5 in wash-off cosmetics at or above 0.1% due to their persistence in water.

Ethylhexyl Hydroxystearate isn't fungal acne safe.

Polysilicone-11 is a film-forming silicone that creates a non-tacky and matte finish on the skin. It's commonly used to improve texture, absorb excess oil, and help active ingredients spread evenly.

Due to its "rubber-like" structure, it stays on the skin's surface instead of being absorbed. On the skin, it creates a flexible layer that enhances wearability and stability.

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. 03Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  4. 04Topically, glycerin does several things at once:
  5. 05Your 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.
  6. 06Aquaporin-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.
  7. 07This 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.
  8. 08Just know very high concentrations (>40%) can feel tacky in low humidity.
  9. 09Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  10. 10Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
  11. 11It 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.
  12. 12On 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.
  13. 13Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
  14. 14You'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.
  15. 15Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
  16. 16Safety-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.
  17. 17Adverse 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.
  18. 18Sodium Phytate is the synthetic salt form of phytic acid. Phytic acid is an antioxidant and can be found in plant seeds.
  19. 19Sodium Phytate is a chelating agent. Chelating agents help prevent metals from binding to water. This helps stabilize the ingredients and the product.
  20. 20Tocopherol is a fat-soluble antioxidant known as Vitamin E.
Source · skinsort.com ⟶
02

Product index

Related product references

03

Comparison edit

Read side by side

Continue reading

Related articles