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Skin science article

Paula's Choice Weightless Body Treatment 2% BHA Versus Curology Custom Serum (Niacinamide 4%, Clindamycin 1%, Azelaic 4%)

Paula's Choice Weightless Body Treatment 2% BHA Versus Curology Custom Serum (Niacinamide 4%, Clindamycin 1%, Azelaic 4%) What's inside Key Ingredients Benefits Concerns Ingredients Side-by-side Water Butylene Glycol Cetyl Alcohol PPG-14 Butyl Ether Salicylic

Paula's Choice Weightless Body Treatment 2% BHA Versus Curology Custom Serum (Niacinamide 4%, Clindamycin 1%, Azelaic 4%)

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Butylene Glycol

Cetyl Alcohol

PPG-14 Butyl Ether

Salicylic Acid

Dimethicone

Tocopheryl Acetate

Chamomilla Recutita Flower Extract

Epilobium Angustifolium Extract

Camellia Oleifera Leaf Extract

Vanilla Planifolia Fruit Extract

Bisabolol

Allantoin

Cyclopentasiloxane

Cyclohexasiloxane

Dimethiconol

PEG-40 Stearate

Sorbitan Stearate

Pvm/Ma Decadiene Crosspolymer

Polyacrylamide

C13-14 Isoparaffin

Laureth-7

Disodium EDTA

Sodium Hydroxide

Hexylene Glycol

Caprylyl Glycol

Caprylic/Capric Triglyceride

Ethylhexylglycerin

Phenoxyethanol

Water, Butylene Glycol, Cetyl Alcohol, PPG-14 Butyl Ether, Salicylic Acid, Dimethicone, Tocopheryl Acetate, Chamomilla Recutita Flower Extract, Epilobium Angustifolium Extract, Camellia Oleifera Leaf Extract, Vanilla Planifolia Fruit Extract, Bisabolol, Allantoin, Cyclopentasiloxane, Cyclohexasiloxane, Dimethiconol, PEG-40 Stearate, Sorbitan Stearate, Pvm/Ma Decadiene Crosspolymer, Polyacrylamide, C13-14 Isoparaffin, Laureth-7, Disodium EDTA, Sodium Hydroxide, Hexylene Glycol, Caprylyl Glycol, Caprylic/Capric Triglyceride, Ethylhexylglycerin, Phenoxyethanol

Niacinamide 4%

Clindamycin 1%

Azelaic Acid 4%

Aloe Barbadensis Leaf Juice

Maltodextrin

Triethylene Glycol

Niacinamide 4%, Clindamycin 1%, Azelaic Acid 4%, Aloe Barbadensis Leaf Juice, C13-14 Isoparaffin, Caprylic/Capric Triglyceride, Water, Laureth-7, Maltodextrin, Phenoxyethanol, Polyacrylamide, Tocopheryl Acetate, Triethylene 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.

C13-14 Isoparaffin is a synthetic emollient, solvent, and thickening agent. It helps soften skin and improves spreadability without leaving a greasy residue.

This ingredient has been found to be non-sensitizing and safe for use in cosmetics.

Two things floating around online that cause fear-mongering:

There's one scary-sounding study related to kidney tumors in male rats; this depends on a protein called alpha-2u-globulin that binds the ingredient and clogs up kidney cells. Female rats barely make this protein, and humans don't make it at all so this effect cannot happen to us. Regulatory bodies have states this rat-only pathway shouldn't be used to judge human risk.

The other thing you'll see is 1,4-dioxane being a trace byproduct that can form during manufacturing of petroleum-derived ingredients. This is a real, but heavily managed/monitored issue. This byproduct is removed through purification steps before the ingredients goes into the formula. Regulatory bodies also actively monitor residual levels for safety.

One last thing to note: this ingredient is a pure hydrocarbon with no fatty-acid or ester chains for Malassezia to feed on, so it's considered fungal acne safe.

Caprylic/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.

Though 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.

In practice, that translates to a long shelf life and a consistently elegant skin feel.

While 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.

Fractionated 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.

This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.

This 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 at concentrations as low as 0.2%.

Laureth-7 is created by the ethoxylation of lauryl alcohol using ethylene oxide. Lauryl alcohol is a fatty alcohol with hydrating properties.

This ingredient is an emulsifier and cleansing ingredient. As an emulsifier, it is used to prevent ingredients from separating. It also helps cleanse the skin by gathering dirt, oil, and pollutants to be rinsed away.

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.

Polyacrylamide is a synthetic polymer. It is used to stabilize products and bind ingredients. When hydrated, Polyacrylamide forms a soft gel.

Polyacrylamide is low-toxicity. If source properly, it is deemed safe to use in cosmetics.

It should be noted the precursor to Polyacrylamide is acrylamide. Acrylamide is a carcinogen. Most reputable sources of Polyacrylamide will screen for residual acrylamide to make sure the count is in a safe range. Acrylamide is not able to be absorbed through the skin.

We recommend speaking with a professional if you have concerns.

Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.

Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

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. 06Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.
  7. 07Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.
  8. 08It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.
  9. 09Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.
  10. 10A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.
  11. 11Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.
  12. 12What it does:
  13. 13Dimethicone comes in different viscosities:
  14. 14Depending on the viscosity, dimethicone has different properties.
  15. 15Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.
  16. 16This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.
  17. 17Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.
  18. 18Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  19. 19Topically, glycerin does several things at once:
  20. 20Your 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.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

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