La Roche-Posay Effaclar Duo Dual Action Acne Cleanser
A highly rated face cleanser that contains aha, benzoyl peroxide, exfoliants, hyaluronic acid and niacinamide.
Overview
What it is
Face cleanser with 23 ingredients that contains AHA, benzoyl peroxide, exfoliants, hyaluronic acid and niacinamide
Cool Features
It is fungal acne (malassezia) safe and reef safe
Suited For
It has ingredients that are good for fighting acne, anti aging, dry skin, brightening skin, sensitive skin, oily skin, reducing pores, scar healing, dark spots and better texture
Free From
It doesn't contain any harsh alcohols, common allergens, fragrances, oils, parabens, silicones or sulfates
Fun facts
La Roche-Posay is from France. This product is used in 8 routines created by our community.
We independently verify ingredients and our claims are backed by peer-reviewed research. Does this product need an update? Let us know.
About this product
Ingredients List
Dive into the full list of ingredients.
Benzoyl Peroxide 4%
Water
Skin ConditioningGlycerin
HumectantPropylene Glycol
HumectantCocamidopropyl Hydroxysultaine
CleansingSodium C14-16 Olefin Sulfonate
CleansingXanthan Gum
EmulsifyingPotassium Hydroxide
BufferingSodium Chloride
MaskingSodium Citrate
BufferingNiacinamide
SmoothingSodium Hyaluronate
HumectantCapryloyl Salicylic Acid
ExfoliatingPropanediol
SolventDiethylhexyl Sodium Sulfosuccinate
CleansingCarbomer
Emulsion StabilisingBenzoic Acid
MaskingPentylene Glycol
Skin ConditioningSodium Hydroxide
BufferingGlycolic Acid
BufferingTetrasodium EDTA
Trisodium Ethylenediamine Disuccinate
Citric Acid
Buffering
Active Ingredients:
Benzoyl Peroxide 4%
Inactive Ingredients:
Water, Glycerin, Propylene Glycol, Cocamidopropyl Hydroxysultaine, Sodium C14-16 Olefin Sulfonate, Xanthan Gum, Potassium Hydroxide, Sodium Chloride, Sodium Citrate, Niacinamide, Sodium Hyaluronate, Capryloyl Salicylic Acid, Propanediol, Diethylhexyl Sodium Sulfosuccinate, Carbomer, Benzoic Acid, Pentylene Glycol, Sodium Hydroxide, Glycolic Acid, Tetrasodium EDTA, Trisodium Ethylenediamine Disuccinate, Citric Acid
Key Ingredients
Benefits
Concerns
Ingredients Explained
Benzoyl Peroxide is famous for fighting acne. This is because it does a variety of tasks on the skin: it helps reduce excess oil, kill bacteria, and clear out dead skin cells. In other words, it is effective at unclogging pores.
These properties make it great at fighting different types of acne, including cystic and inflammatory types of acne.
When targeting the bacteria in your pores, Benzoyl Peroxide has been shown to kill the bacteria without causing sensitivity. It also helps keep your skin's natural bacteria and biome balanced. Having a healthy biome protects your skin from external harmful factors.
Once Benzoyl Peroxide is absorbed into the skin, our bodies turn it into benzoic acid and quickly exits in urine.
When using Benzoyl Peroxide, it may be irritating for some people due to a variety of reasons, such as a broken skin barrier or just an allergic reaction. We recommend speaking with a professional about using this ingredient if you have concerns.
Learn more about Benzoyl PeroxideWater. 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. Stay hydrated!
Learn more about WaterGlycerin is already naturally found in your skin. It helps moisturize and protect your skin.
A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.
As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.
Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.
Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.
In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.
This ingredient is organic, colorless, odorless, and non-toxic.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Learn more about GlycerinPropylene Glycol is an odorless, colorless liquid. As a humectant, it helps skin retain moisture. It also aids in delivering active ingredients.
Another role of this ingredient is preventing a product from melting or freezing. Propylene glycol also adds antimicrobrial properties to a product, elongating product lifespan.
This ingredient is considered an organic alcohol and commonly added into both cosmetics and foods.
Those with sensitive skin or conditions may develop a rash when using this ingredient.
Learn more about Propylene GlycolCocamidopropyl Hydroxysultaine is a synthetic cleansing agent, though it is derived from coconut oil.
It is used to enhance the texture of products by boosting lather and thickening the texture. As a cleanser, Cocamidopropyl Hydroxysultaine is mild.
Sodium C14-16 Olefin Sulfonate is a cleansing agent made from a mixture of long chain sulfonate salts. It can also help produce foam.
This ingredient may be drying. We recommend speaking with a professional if you have concerns.
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.
Learn more about Xanthan GumPotassium hydroxide is commonly known as caustic potash. It is used to fix the pH of a product or as a cleaning agent in soap. In cleansers, it is used for the saponification of oils.
Sapnification is the process of creating fatty acid metal salts from triglycerides and a strong base. During this process, Potassium Hydroxide is used up and is not present in the final product.
Using high concentrations of Potassium Hydroxide have shown to irritate the skin.
Learn more about Potassium HydroxideChances are, you eat sodium chloride every day. Sodium Chloride is also known as table salt.
This ingredient has many purposes in skincare: thickener, emulsifier, and exfoliator.
You'll most likely find this ingredient in cleansers where it is used to create a gel-like texture. As an emulsifier, it also prevents ingredients from separating.
There is much debate on whether this ingredient is comedogenic. The short answer - comedogenic ratings don't tell the whole story. Learn more about comegodenic ratings here.
The concensus about this ingredient causing acne seems to be divided. Research is needed to understand if this ingredient does cause acne.
Scrubs may use salt as the primary exfoliating ingredient.
Learn more about Sodium ChlorideSodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.
Its main functions are to maintain the pH of a product and neutralize metal ions.
The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).
Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.
Learn more about Sodium CitrateNiacinamide has emerged as an all-star ingredient due to its many benefits.
It is known to treat acne by reducing inflammation. It also helps fade dark-spots and strengthen the skin by promoting the growth of the ceramide barrier.
Other benefits include smoothing wrinkles and minimizing redness.
The cherry on top? Niacinamide can also help build keratin, a protein that keeps skin firm.
When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.
Niacinamide can be mixed with other ingredients to boost benefits. For instance, it has shown to be effective when used with copper, folic acid, and zinc to treat acne.
Learn more about NiacinamideSodium Hyaluronate is hyaluronic acid's salt form. It is commonly derived from the sodium salt of hyaluronic acid.
Like hyaluronic acid, it is great at holding water and acts as a humectant. This makes it a great skin hydrating ingredient.
Sodium Hyaluronate is naturally occurring in our bodies and is mostly found in eye fluid and joints.
These are some other common types of Hyaluronic Acid:
Learn more about Sodium HyaluronateCapryloyl Salicylic Acid comes from salicylic acid, the famous acne-fighting BHA.
It usually goes by a more common name of LHA, or lipohydroxy acid.
Like salicylic acid, this ingredient is a chemical exfoliant that can help break down the oil in your pores and reduce inflammation.
Though studies for LHA do show it to be less effective than salicylic acid. To be fair, salicylic acid is the reigning monarch of acne treatments.
However, a study from 2009 found LHA to be comparable to BPO, making it a good alternative for people with sensitive skin. Another study of 14 patients found a significant decrease in comedones after using LHA.
Another pro of LHA? It is less irritating than salicylic acid due to its large molecule size.
Large molecules cannot penetrate skin as well, so they are gentler on the skin. LHA is much less penetrative than salicylic acid.
An in-vitro study (not done on a living organism) found only 6% of LHA penetrated past the statum corneum compared to 58% of salicylic acid. An in-vivo (done on a living organism) analysis revealed ~17% of LHA was still present in the top layer of skin after 4 days, versus ~9% of salicylic acid.
Interestingly, a study from 2008 found LHA comparable to another famous acid, glycolic acid.
This study found about 10% of LHA is as effective as 20-50% of glycolic acid in treating hyperpigmentation and fine-lines.
Hydroxy acids have been found to stimulate skin protein, lipids, and thermal thickening. This may have anti-aging benefits.
Learn more about Capryloyl Salicylic AcidPropanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
Learn more about PropanediolWe don't have a description for Diethylhexyl Sodium Sulfosuccinate yet.
Carbomer is a polymer of acrylic acid. Its main role is to create a gel consistency.
A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.
Benzoic Acid is used to preserve and adjust the pH of products.
The antimicrobial property of Benzoic Acid helps elongate a product's shelf life. Its main role is to reduce fungi growth and is not found to be effective at fighting bacteria. Therefore Benzoic Acid is always added along with other preservatives.
In its pure form, Benzoic Acid looks like a white crystalline solid. It has slight solubility in water.
The name of Benzoic Acid comes from gum benzoin, which used to be the sole source of deriving this ingredient. Benzoic Acid is the most simple aromatic carboxylic acid.
Benzoic Acid is naturally occuring in strawberries, mustard, cinnamon, and cloves. It has a slight scent but is not considered to be a fragrance.
Learn more about Benzoic AcidPentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.
The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.
This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.
Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.
Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.
Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.
Learn more about Pentylene GlycolSodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.
In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.
"Alkaline" refers to a high pH level. A low pH level would be considered acidic.
Learn more about Sodium HydroxideGlycolic Acid is arguably the most famous AHA with a ton of research to back up its benefits.
Its main role is to remove the top layer of dead skin cells, allowing newer skin cells to emerge.
Specifically, AHAs work by breaking down the structural "glue" holding the old skin cells in place. Getting rid of the old skin cells allows skin to regenerate newer skin cells in its place. A build up of dead skin cells can lead to tired and dull looking skin.
Due to this, glycolic acid helps with:
Fun fact: Glycolic acid increases skin hydration by playing a role in creating molecules that create hyaluronic acid naturally.
When starting glycolic Acid, it is normal to feel slight stinging.
The pH value and concentration of glycolic acid play a role in the effectiveness of the product. Concentrations between 5-20% glycolic acid have been shown to be effective in clinical studies.
Recent studies have shown Glycolic Acid may protect the skin against UV damage. However, you should always wear SPF, especially when using exfoliants.
Read more about some other popular AHA's here:
Learn more about Glycolic AcidTetrasodium EDTA is the salt formed from neutralizing ethylenediamine tetraacetic acid with sodium hydroxide. It is a chelating agent and used to prevent metal ions from binding to other ingredients. This helps keep the product and ingredients stable.
Tetrasodium EDTA comes as a white solid and is soluble in water.
Trisodium Ethylenediamine Disuccinate is used to help stabilize a product.
It is a chelating agent, meaning it helps prevent metal ions from binding to other ingredients. This prevents unwanted reactions in products. Metal ions can come into a product via the water ingredient. They are found in trace amounts and are not known to be harmful.
Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).
As an AHA, Citric Acid removes the top layer of skin cells from the newer layer of skin underneath. This helps skin to remove dark spots and even out skin tone.
If you spot Citric Acid near the end of an ingredient list, it's likely there as a pH adjuster rather than an active ingredient.
Read more about some other popular AHA's here:
Learn more about Citric AcidReviews
Where it's from
La Roche-Posay is a French brand
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Read more about us· Updated March 3, 2025 • Added by KadenLunt