Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Skin Perfecting 8% AHA Gel Exfoliant Versus Summer Fridays Soft Reset AHA Exfoliating Solution

Paula's Choice Skin Perfecting 8% AHA Gel Exfoliant Versus Summer Fridays Soft Reset AHA Exfoliating Solution This smoothing exfoliator is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin. This smoothing exfoliator is formu

Paula's Choice Skin Perfecting 8% AHA Gel Exfoliant Versus Summer Fridays Soft Reset AHA Exfoliating Solution

This smoothing exfoliator is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin.

This smoothing exfoliator is formulated around Lactic Acid and Glycolic Acid to refine skin texture and brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycolic Acid

Sodium Hydroxide

Chamomilla Recutita Flower Extract

Aloe Ferox Leaf Juice Extract

Camellia Oleifera Leaf Extract

Sodium Hyaluronate

Panthenol

Sodium PCA

Propylene Glycol

Butylene Glycol

Hydroxyethylcellulose

Polyquaternium-10

Phenoxyethanol

Sodium Benzoate

Water, Glycolic Acid, Sodium Hydroxide, Chamomilla Recutita Flower Extract, Aloe Ferox Leaf Juice Extract, Camellia Oleifera Leaf Extract, Sodium Hyaluronate, Panthenol, Sodium PCA, Propylene Glycol, Butylene Glycol, Hydroxyethylcellulose, Polyquaternium-10, Phenoxyethanol, Sodium Benzoate

Lactic Acid

Propanediol

Aloe Barbadensis Leaf Juice

Glycerin

Niacinamide

Sodium Citrate

Citric Acid

Acer Saccharum Extract

Camellia Sinensis Leaf Extract

Citrus Aurantium Dulcis Fruit Extract

Citrus Limon Fruit Extract

Saccharum Officinarum Extract

Vaccinium Myrtillus Fruit Extract

Chamomilla Recutita Extract

Curcuma Longa Root Extract

Xanthan Gum

Caprylyl Glycol

Tetrasodium Glutamate Diacetate

Ascorbyl Glucoside

Water, Lactic Acid, Propanediol, Aloe Barbadensis Leaf Juice, Glycerin, Glycolic Acid, Niacinamide, Sodium Hyaluronate, Sodium Citrate, Phenoxyethanol, Citric Acid, Acer Saccharum Extract, Camellia Sinensis Leaf Extract, Citrus Aurantium Dulcis Fruit Extract, Citrus Limon Fruit Extract, Saccharum Officinarum Extract, Vaccinium Myrtillus Fruit Extract, Chamomilla Recutita Extract, Curcuma Longa Root Extract, Xanthan Gum, Caprylyl Glycol, Tetrasodium Glutamate Diacetate, Ascorbyl Glucoside

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.

Glycolic Acid is arguably the most famous alpha hydroxy acid (AHA) with tons of research backing its benefits.

It is found naturally in sugar cane but the form used in skincare is usually synthetic for purity and stability.

Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.

AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.

Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.

Overall, glycolic acid helps with:

Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.

To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).

The pH and concentration of a product are key to its effectiveness:

It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.

Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.

If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.

Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.

Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.

Read more about some other popular AHA's here:

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.

Sodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.

In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

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. 03Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  4. 04Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  5. 05Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
  6. 06C13-15 Alkane is a group of alkanes with 13 to 15 carbon atoms in the alkyl chain.
  7. 07It is a solvent and texture enhancer. Solvents are used to keep ingredients together in a product. They can help dissolve ingredients to stable bases or help evenly distribute ingredients throughout the product.
  8. 08Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
  9. 09Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
  10. 10In practice, that translates to a long shelf life and a consistently elegant skin feel.
  11. 11While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
  12. 12Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
  13. 13This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
  14. 14This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures…
  15. 15Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
  16. 16Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
  17. 17However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
  18. 18Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.
  19. 19In skincare formulas, citric acid can:
  20. 20While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side