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La Roche-Posay Effaclar Duo [+] Spf 30

Effaclar Duo [+] Spf 30

Visibly correct imperfections with the La Roche-Posay Effaclar Duo+ SPF30; a non-sticky formula that works to reduce the appearance of blemishes and reveal a refined complexion. Ideal for oily and blemish-prone skin types, the correcting formula penetrates and clears blocked pores in order to visibly reduce blackheads and other impurities. When exposed to daily UV, imperfections often worsen and can lead to unwanted hyperpigmentation. Effaclar Duo+ boasts SPF30, which shields skin from damaging rays, protects against free radicals and prevents the appearance of hyperpigmentation.
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Skim through

Ingredient name what-it-does irr., com. ID-Rating
Aqua/Water solvent
Octocrylene sunscreen
Glycerin skin-identical ingredient, moisturizer/​humectant 0, 0 superstar
Homosalate sunscreen
Ethylhexyl Salicylate sunscreen 0, 0
Alcohol Denat antimicrobial/​antibacterial, solvent, viscosity controlling icky
Niacinamide cell-communicating ingredient, skin brightening, anti-acne, moisturizer/​humectant superstar
Butyl Methoxydibenzoylmethane sunscreen goodie
Dimethicone emollient 0, 1
Sorbitan Stearate emulsifying 1, 0
Silica viscosity controlling
Isopropyl Lauroyl Sarcosinate emollient
Styrene/Acrylates Copolymer
Propylene Glycol moisturizer/​humectant, solvent 0, 0
Potassium Cetyl Phosphate emulsifying, surfactant/​cleansing
Diisopropyl Sebacate emollient, solvent
PEG-20 moisturizer/​humectant, solvent
PEG-8 Laurate emulsifying, surfactant/​cleansing
Zinc Pca anti-acne, moisturizer/​humectant goodie
Dimethicone/Vinyl Dimethicone Crosspolymer viscosity controlling
2-Oleamido-1,3-Octadecanediol
Inulin Lauryl Carbamate surfactant/​cleansing, emulsifying
Carnosine antioxidant, cell-communicating ingredient goodie
Poloxamer 338 emulsifying, surfactant/​cleansing
Ammonium Polyacryloyldimethyl Taurate viscosity controlling
Disodium EDTA chelating
Sucrose Cocoate emulsifying
Capryloyl Salicylic Acid exfoliant goodie
Xanthan Gum viscosity controlling
T-Butyl Alcohol perfuming, solvent
BHT antioxidant, preservative
Salicylic Acid exfoliant, anti-acne, soothing, preservative superstar
Parfum/Fragrance perfuming icky

La Roche-Posay Effaclar Duo [+] Spf 30
Ingredients explained

Also-called: Aqua;Water | What-it-does: solvent

Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product. 

It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water. 

What-it-does: sunscreen

An oil-soluble chemical sunscreen agent that protects skin in the UVB and somewhat in the UVA II range with a peak absorption of 304 nm. Its protection is not strong enough on its own but it is quite photostable (loses 10% of SPF protection in 95 mins) and is often used to stabilize other photo-unstable UV-filters, for example, Avobenzone. It is also often used to improve the water resistance of the products. 

Octocrylene's safety profile is generally quite good, though a review study in Contact Dermatitis reports an "increasing number of patients with photo contact allergy to octocrylene." Mainly adults with ketoprofen-sensitivity and children with sensitive skin are affected, so if you have a small kid, it is probably better to use octocrylene-free sunscreens.

Glycerin - superstar
Also-called: Glycerol | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
  • A natural moisturizer that’s also in our skin
  • A super common, safe, effective and cheap molecule used for more than 50 years
  • Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
  • Effective from as low as 3% with even more benefits for dry skin at higher concentrations up to 20-40%
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

What-it-does: sunscreen

An oil-soluble chemical sunscreen agent that protects the skin from UVB (295-315 nm) with a peak protection at 306 nm. Homosalate is not a strong UV filter in and of itself (gives only SPF 4.3 protection at max. allowed 10% concentration) and it is not photostable (looses 10% of its SPF protection in 45 mins) so it always has to be combined with other sunscreens for proper protection. Its big advantage, though, is that it is a liquid and is excellent for dissolving other hard to solubilize powder sunscreen agents, like the famous Avobenzone.

Regarding Homosalate's safety profile, we do not have the best news. In-vitro (made in the labs) studies have shown that it might have some estrogenic activity. Do not panic, these studies were not conducted on real humans under real world conditions. Still, if you are a 'better safe than sorry' type, be careful when using Homosalate containing sunscreens long-term and full-body.

Also-called: Octyl Salicylate, Octisalate | What-it-does: sunscreen | Irritancy: 0 | Comedogenicity: 0

A colorless to light yellowish oily liquid that works as a UVB (280-320nm) sunscreen filter with a peak absorbance at 306 nm. It's not a strong filter in itself, it's always used in combination with other sunscreen agents to further enhance the SPF and to solubilize other solid UV filters.

It has a good safety profile and is allowed to be used at a max concentration of 5% both in the US and in Europe (10% is allowed in Japan).

  • It's a super common and super debated skincare ingredient
  • It has several benefits: great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial
  • It can be very drying if it's in the first few ingredients on an ingredient list
  • Some experts even think that regular exposure to alcohol damages skin barrier and causes inflammation though it's a debated opinion (read more in geeky details tab)
Read all the geeky details about Alcohol Denat. here >>

Niacinamide - superstar
Also-called: vitamin B3, nicotinamide | What-it-does: cell-communicating ingredient, skin brightening, anti-acne, moisturizer/humectant
  • A multi-functional skincare superstar with several proven benefits for the skin
  • Great anti-aging, wrinkle smoothing ingredient used at 4-5% concentration
  • Fades brown spots alone or in combination with amino sugar, acetyl glucosamine
  • Increases ceramide synthesis that results in a stronger, healthier skin barrier and better skin hydration
  • Can help to improve several skin conditions including acne, rosacea, and atopic dermatitis
Read all the geeky details about Niacinamide here >>

Also-called: Avobenzone | What-it-does: sunscreen

The famous Avobenzone. It is a special snowflake as it is the only globally available chemical sunscreen agent that provides proper UVA protection (in the US, new generation sunscreen agents are not approved because of impossible FDA regulations). It is the global gold standard of UVA protection and is the most used UVA sunscreen in the world. 

It gives very good protection across the whole UVA range (310-400 nm that is both UVA1 and UVA2) with a peak protection at 360 nm. The problem with it, though, is that it is not photostable and degrades in the sunlight. Wikipedia says that avobenzone loses 36% of its UV-absorption capacity after just one hour of sunlight (yep, this is one of the reasons why sunscreens have to be reapplied after a few hours).

What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1

Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.

As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity. 

What-it-does: emulsifying | Irritancy: 1 | Comedogenicity: 0

A popular, vegetable-derived oil-loving emulsifier that helps water to mix with oil. In itself, it is suitable for water-in-oil emulsions (where water droplets are dispersed in oil), but it is more often used as a co-emulsifier next to other, water-loving emulsifiers. 

Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the fatty acid Stearic Acid, that creates a partly water (the sorbitan part) and partly oil soluble (stearic part) molecule. 

A white powdery thing that's the major component of glass and sand. In cosmetics, it’s often in products that are supposed to keep your skin matte as it has great oil-absorbing abilities. It’s also used as a helper ingredient to thicken up products or suspend insoluble particles. 

What-it-does: emollient

A colorless to light yellow oily fluid that works as an emollient (makes your skin nice and smooth) and a solvent for poorly soluble materials, such as sunscreen agents. It also has a light touch, low odor, and good spreadability. It is derived from the amino acid sarcosine and is biodegradable.

A film-forming polymer (big molecule from repeated subunits) to create water-resistant sunscreen formulas. It also improves the SPF value of sunscreen formulas (approx. 11-18% boost in SPF per 1% Styrene/Acrylates Copolymer). 

What-it-does: moisturizer/humectant, solvent | Irritancy: 0 | Comedogenicity: 0
  • It's a helper ingredient that improves the freeze-thaw stability of products
  • It's also a solvent, humectant and to some extent a penetration enhancer
  • It has a bad reputation among natural cosmetics advocates but cosmetic scientists and toxicology experts do not agree (read more in the geeky details section)
Read all the geeky details about Propylene Glycol here >>

A white to beige powder that is described as the golden standard emulsifier for emulsions (oil+water mixtures) that are difficult to stabilize. It is especially popular in sunscreens as it can boost SPF protection and increase the water-resistance of the formula. 

What-it-does: emollient, solvent

A clear, colorless, practically odorless, light liquid that works as a handy helper ingredient in sunscreen formulas. It helps to create high-SPF formulas with reduced concentrations of UV-filters and it also helps to create cosmetically elegant formulas (and that's no easy feat when it comes to sunscreens). It absorbs rapidly, makes the product easily spreadable and reduces greasiness coming from the oil-soluble sunscreen agents.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Zinc Pca - goodie

If you have oily, acne-prone skin, Zinc PCA is one of the actives to put on your "TO TRY" list.

It's a synergistic association of two great things: Zinc and L-PCA. The Zinc part is there to help normalize sebum production and limit the proliferation of evil acne-causing bacteria. L-PCA stands for pyrrolidone carboxylic acid and it's a key molecule in the skin that helps with processes of hydration and energy (it's actually an NMF, a natural moisturizing factor).

What-it-does: viscosity controlling

A white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. It also has some oil and sebum absorption capabilities. 

We don't have description for this ingredient yet.

polymeric (big molecule from repeated subunits) emulsifier that comes from Inulin, a naturally occurring polysaccharide found in the roots and rhizomes of several plants. The emulsifier is obtained by adding oil-loving chains onto inulin. The resulting copolymer can emulsify high amounts of oil and can stabilize oil droplets or non-water soluble particles so that they do not clump together in the formula. 

Carnosine - goodie

Though its name does not reveal it, Carnosine is a peptide, a small, two amino acid (β-Ala-His) one. It is naturally present in high concentrations in muscle and brain tissues, but the one used in cosmetic products is biomimetic, meaning that it is synthetically produced in a lab to copy the natural thing. 

A 2017 review paper on topical peptides writes about Carnosine that it is a "well-documented aqueous antioxidant with wound healing activity".  

We don't have description for this ingredient yet.

There is not much info about this guy in itself other than it helps to thicken up products and stabilize oil-in-water emulsions. It usually comes to the formula as part of some thickener complex. For example, coupled with isohexadecane and polysorbate 80, the trio forms an instant gel upon mixing with water. 

What-it-does: chelating

Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes.

It is typically used in tiny amounts, around 0.1% or less.

What-it-does: emulsifying

We don't have description for this ingredient yet.

Also-called: LHA | What-it-does: exfoliant

We don't have description for this ingredient yet.

It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range. 

Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415). 

What-it-does: perfuming, solvent

A clear liquid with a camphor-like odor that is used as a solvent

Also-called: Butylated Hydroxy Toluene | What-it-does: antioxidant, preservative

It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.

There is some controversy around BHT. It's not a new ingredient, it has been used both as a food and cosmetics additive since the 1970s. Plenty of studies tried to examine if it's a carcinogen or not. This Truth in Aging article details the situation and also writes that all these studies examine BHT when taken orally.

Salicylic Acid - superstar
Also-called: BHA | What-it-does: exfoliant, anti-acne, soothing, preservative
  • It's one of the gold standard ingredients for treating problem skin
  • It can exfoliate skin both on the surface and in the pores
  • It's a potent anti-inflammatory agent
  • It's more effective for treating blackheads than acne
  • For acne combine it with antibacterial agents like benzoyl peroxide or azelaic acid
Read all the geeky details about Salicylic Acid here >>

Also-called: Fragrance, Parfum | What-it-does: perfuming

Exactly what it sounds: nice smelling stuff put into cosmetic products so that the end product also smells nice. Fragrance in the US and parfum in the EU is a generic term on the ingredient list that is made up of 30 to 50 chemicals on average (but it can have as much as 200 components!). 

If you are someone who likes to know what you put on your face then fragrance is not your best friend - there's no way to know what’s really in it.  

You may also want to take a look at...

what‑it‑does solvent
Normal (well kind of - it's purified and deionized) water. Usually the main solvent in cosmetic products. [more]
what‑it‑does sunscreen
An oil-soluble chemical sunscreen agent that protects skin in the UVB and somewhat in the UVA II range with a peak absorption of 304 nm. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
A real oldie but a goodie. Great natural moisturizer and skin-identical ingredient that plays an important role in skin hydration and general skin health. [more]
what‑it‑does sunscreen
An oil-soluble chemical sunscreen agent that protects the skin from UVB (295-315 nm) with a peak protection at 306 nm. Homosalate is not a strong UV filter in and of itself (gives only SPF 4.3 protection at max. [more]
what‑it‑does sunscreen
irritancy, com. 0, 0
A colorless to light yellowish oily liquid that works as a UVB (280-320nm) sunscreen filter with a peak absorbance at 306 nm. It's not a strong filter in itself, it's always used in combination with other sunscreen agents. [more]
what‑it‑does antimicrobial/antibacterial | solvent | viscosity controlling
Alcohol with some additives to make it unconsumable. It is great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent, and antimicrobial. In large amounts, it can be very drying to the skin. [more]
what‑it‑does cell-communicating ingredient | skin brightening | anti-acne | moisturizer/humectant
A multi-functional skincare superstar that has clinically proven anti-aging, skin lightening, anti-inflammatory and barrier repair properties. [more]
what‑it‑does sunscreen
Avobenzone - the only globally available chemical sunscreen that gives proper UVA protection. It is not photostable so has to be combined with ingredients that help to stabilize it. [more]
what‑it‑does emollient
irritancy, com. 0, 1
A very common silicone that gives both skin and hair a silky smooth feel. It also forms a protective barrier on the skin and fills in fine lines. Also used for scar treatment. [more]
what‑it‑does emulsifying
irritancy, com. 1, 0
A popular, vegetable-derived oil-loving emulsifier that helps water to mix with oil. In itself, it is suitable for water-in-oil emulsions (where water droplets are dispersed in oil), but it is more often used as a co-emulsifier next to other, water-loving emulsifiers.  Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the fatty [more]
what‑it‑does viscosity controlling
A white powdery thing that can mattify the skin and thicken up cosmetic products. [more]
what‑it‑does emollient
A colorless to light yellow oily fluid that works as an emollient (makes your skin nice and smooth) and a solvent for poorly soluble materials, such as sunscreen agents. [more]
A film-forming polymer (big molecule from repeated subunits) to create water-resistant sunscreen formulas.  [more]
what‑it‑does moisturizer/humectant | solvent
irritancy, com. 0, 0
A common glycol that improves the freeze-thaw stability of products. It's also a solvent, humectant and to some extent a penetration enhancer. [more]
what‑it‑does emulsifying | surfactant/cleansing
A white to beige powder that is the golden standard emulsifier for emulsions (oil+water mixtures) that are difficult to stabilize. [more]
what‑it‑does emollient | solvent
A light liquid that works as a handy helper ingredient in sunscreen formulas. It both helps to boost SPF protection as well as to create light, elegant formulas. [more]
what‑it‑does moisturizer/humectant | solvent
what‑it‑does emulsifying | surfactant/cleansing
what‑it‑does anti-acne | moisturizer/humectant
A synergistic combination of Zinc and l-PCA that can reduce sebum production and limit the proliferation of evil acne-causing bacteria. A goodie for oily, acne-prone skin. [more]
what‑it‑does viscosity controlling
A white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. [more]
what‑it‑does surfactant/cleansing | emulsifying
A polymeric (big molecule from repeated subunits) emulsifier that comes from Inulin. It can emulsify high amounts of oil and stabilize oil droplets or non-water soluble particles so that they do not clump together.  [more]
what‑it‑does antioxidant | cell-communicating ingredient
A biomimetic peptide with antioxidant, anti-glycation and maybe collagen boosting abilities. It also protects against damages caused by infrared radiation. [more]
what‑it‑does emulsifying | surfactant/cleansing
what‑it‑does viscosity controlling
A polymer that helps to thicken up products and stabilize oil-in-water emulsions. [more]
what‑it‑does chelating
Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes. [more]
what‑it‑does emulsifying
what‑it‑does exfoliant
what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does perfuming | solvent
A clear liquid with a camphor-like odor that is used as a solvent.  [more]
what‑it‑does antioxidant | preservative
It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.There is some controversy around BHT. [more]
what‑it‑does exfoliant | anti-acne | soothing | preservative
One of the gold standard ingredients for treating problem skin. It can exfoliate skin both on the surface and in the pores and it's a potent anti-inflammatory agent. [more]
what‑it‑does perfuming
The generic term for nice smelling stuff put into cosmetic products so that the end product also smells nice. It is made up of 30 to 50 chemicals on average. [more]