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Skin science article

La Roche-Posay EFFACLAR K+ Versus Paula's Choice BHA 9 Treatment

La Roche-Posay EFFACLAR K+ Versus Paula's Choice BHA 9 Treatment This oil-control moisturizer is formulated around Salicylic Acid and Zinc PCA to balance excess oil and refine the look of pores. This acne treatment is formulated around Salicylic Acid to clear

La Roche-Posay EFFACLAR K+ Versus Paula's Choice BHA 9 Treatment

This oil-control moisturizer is formulated around Salicylic Acid and Zinc PCA to balance excess oil and refine the look of pores.

This acne treatment is formulated around Salicylic Acid to clear breakouts and refine the look of pores.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Propylene Glycol

Octyldodecanol

Dimethicone

PEG-100 Stearate

Glyceryl Stearate

Salicylic Acid

Ammonium Polyacryloyldimethyl Taurate

Zinc PCA

Sarcosine

Sodium Hydroxide

Silica

Silica Silylate

Perlite

Carnosine

Disodium EDTA

Capryloyl Salicylic Acid

Xanthan Gum

Pentylene Glycol

Acrylates Copolymer

Cetyl Alcohol

Butylene Glycol

Tocopherol

Parfum

Water, Propylene Glycol, Octyldodecanol, Dimethicone, PEG-100 Stearate, Glyceryl Stearate, Salicylic Acid, Ammonium Polyacryloyldimethyl Taurate, Zinc PCA, Sarcosine, Sodium Hydroxide, Silica, Silica Silylate, Perlite, Carnosine, Disodium EDTA, Capryloyl Salicylic Acid, Xanthan Gum, Pentylene Glycol, Acrylates Copolymer, Cetyl Alcohol, Butylene Glycol, Tocopherol, Parfum

PEG-75 Stearate

PEG-8

Glycerin

Avena Sativa Kernel Extract

Boerhavia Diffusa Root Extract

Sea Whip Extract

Arginine

Polysorbate 20

Propylene Glycol, PEG-75 Stearate, PEG-8, Water, Salicylic Acid, Glycerin, Avena Sativa Kernel Extract, Butylene Glycol, Boerhavia Diffusa Root Extract, Sea Whip Extract, Arginine, Polysorbate 20, Disodium EDTA

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.

Disodium EDTA is a chelating agent. It grabs onto and deactivates metal ions that sneak into your products from water, packaging, or air.

This ingredient mainly works behind the scenes and helps with:

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Propylene Glycol is a synthetic, colorless, odorless liquid that has been a staple in cosmetics for decades. It is a skin conditioning agent, humectant, and solvent.

As a humectant, it draw water to the skin to reduce flaking and restore suppleness. It's also a solvent that helps dissolve other actives and keeps formulas stable across temperature changes.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

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. 03Retinol is one of the most studied anti-aging ingredients in skincare (and for good reason!).
  4. 04It's a form of vitamin A that your skin converts into Retinoic Acid, the active molecule that actually does the work in your cells.
  5. 05That conversion happens in two steps: your skin first turns Retinol into Retinaldehyde (also called Retinal), then turns Retinaldehyde into Retinoic Acid.
  6. 06Retinol is converted to biologically active retinoic acid via retinaldehyde by dehydrogenases in a two-step oxidation process.
  7. 07Each 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.
  8. 08Here is the retinoid family ranked roughly by strength: Retinyl Esters (like Retinyl Palmitate) < Retinol < Retinaldehyde < Retinoic Acid.
  9. 09Retinoid activity increases in that order, while tolerance runs in reverse; retinyl esters are the gentlest and retinoic acid the most irritating.
  10. 10The 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.
  11. 11Once 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.
  12. 12In practice, this means a few things happen in a formula. It:
  13. 13That last two are worth a closer look.
  14. 14A 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…
  15. 15Retinoids more broadly stimulate the skin's synthesis of hyaluronan and other glycosaminoglycans, part of what gives skin a plumper, more hydrated look over time.
  16. 16So even the gentler OTC form is doing real structural work (not just sitting on the surface).
  17. 17It's also worth knowing Retinol isn't only a wrinkle ingredient; it can help with uneven tone, dark spots, rough texture, and the look of pores as well because it speeds up turnover and influences pigment.
  18. 18The research backs this up as well.
  19. 19A pooled analysis of six clinical studies found that 0.1% stabilized retinol improved all signs of photoaging versus vehicle as early as week 4 and through 12 weeks, with only a few mild cases of irritation.
  20. 20Another study comparing concentrations found that 0.3% and 1% Retinol were similarly effective at remodeling photodamaged skin, but 0.3% caused fewer adverse reactions when used daily (a useful reminder that more isn't always better).
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

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