Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Skin Perfecting 2% BHA Liquid Exfoliant Versus Naturium BHA Liquid Exfoliant 2%

Paula's Choice Skin Perfecting 2% BHA Liquid Exfoliant Versus Naturium BHA Liquid Exfoliant 2% This smoothing exfoliator is formulated around Salicylic Acid to refine skin texture and refine the look of pores. What's inside Key Ingredients Benefits Concerns In

Paula's Choice Skin Perfecting 2% BHA Liquid Exfoliant Versus Naturium BHA Liquid Exfoliant 2%

This smoothing exfoliator is formulated around Salicylic Acid to refine skin texture and refine the look of pores.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Methylpropanediol

Butylene Glycol

Salicylic Acid

Polysorbate 20

Camellia Oleifera Leaf Extract

Sodium Hydroxide

Tetrasodium EDTA

Phenoxyethanol

Water, Methylpropanediol, Butylene Glycol, Salicylic Acid, Polysorbate 20, Camellia Oleifera Leaf Extract, Sodium Hydroxide, Tetrasodium EDTA, Phenoxyethanol

Propanediol

Sodium Polyacrylate

Citric Acid

Glycerin

Diglycerin

Citrus Glauca Fruit Extract

Microcitrus Australasica Fruit Extract

Microcitrus Australis Fruit Extract

Hydroxyacetophenone

Carrageenan

Sodium Phytate

Caprylyl Glycol

Phenylpropanol

Tocopherol

Water, Butylene Glycol, Propanediol, Salicylic Acid, Sodium Polyacrylate, Citric Acid, Glycerin, Diglycerin, Citrus Glauca Fruit Extract, Microcitrus Australasica Fruit Extract, Microcitrus Australis Fruit Extract, Hydroxyacetophenone, Carrageenan, Phenoxyethanol, Sodium Phytate, Caprylyl Glycol, Phenylpropanol, Tocopherol

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.

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though 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.

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.

Salicylic Acid (also known as beta hydroxy acid or BHA) is a well-known ingredient for treating skin that struggles with acne and clogged pores. It exfoliates both the skin's surface and deep within the pores to help clear out buildup, control oil, and reduce inflammation.

Unlike AHAs (alpha hydroxy acids), salicylic acid is oil-soluble. This allows it to penetrate into pores which makes it especially effective for treating blackheads and preventing future breakouts.

Salicylic acid is also known for its soothing properties. It has a similar structure to aspirin and can calm inflamed or irritated skin, making it a good option for acne-prone skin that is also sensitive.

Concentrations of 0.5-2% are recognized by the U.S. FDA as an over-the-counter topical acne product.

It can cause irritation and/or dryness if one's skin already has a compromised moisture barrier, so it's best to focus on repairing that before introducing this ingredient into your routine.

While salicylic acid does not increase sun sensitivity, it’s still important to wear sunscreen daily to protect your skin.

If you are looking for the ingredient called BHA or Butylated Hydroxyanisole, click 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. 03Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.
  4. 04It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.
  5. 05The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.
  6. 06Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).
  7. 07True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.
  8. 08Because it is derived from lauric acid, it may not be fungal acne safe.
  9. 09Retinol is one of the most studied anti-aging ingredients in skincare (and for good reason!).
  10. 10It's a form of vitamin A that your skin converts into Retinoic Acid, the active molecule that actually does the work in your cells.
  11. 11That conversion happens in two steps: your skin first turns Retinol into Retinaldehyde (also called Retinal), then turns Retinaldehyde into Retinoic Acid.
  12. 12Retinol is converted to biologically active retinoic acid via retinaldehyde by dehydrogenases in a two-step oxidation process.
  13. 13Each step is a little "upgrade" toward the active form which is part of why Retinol is gentler than prescription Retinoic Acid; your skin does the work gradually. This also explains where Retinol sits in the retinoid family.
  14. 14Here is the retinoid family ranked roughly by strength: Retinyl Esters (like Retinyl Palmitate) < Retinol < Retinaldehyde < Retinoic Acid.
  15. 15Retinoid activity increases in that order, while tolerance runs in reverse; retinyl esters are the gentlest and retinoic acid the most irritating.
  16. 16The more conversion steps an ingredient needs, the gentler (and slower) it tends to be, so Retinol lands in a nice middle spot. It's more effective than the esters, gentler than prescription options.
  17. 17Once it becomes Retinoic Acid, it binds to receptors inside your cells' nuclei (called RARs and RXRs). These receptor pairs bind to specific DNA motifs called retinoic acid response elements and act like switches that turn certain genes on or off.
  18. 18In practice, this means a few things happen in a formula. It:
  19. 19That last two are worth a closer look.
  20. 20A study that tested Retinol directly (not just prescription Retinoic Acid) found that four weeks of retinol thickened the epidermis and switched on the genes for Collagen I and Collagen III, with more procollagen I and III showing up in the skin. An…
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side