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La Roche-Posay Effaclar Duo Acne Spot Treatment

Effaclar Duo Acne Spot Treatment

This acne spot treatment reduces the number and severity of acne blemishes and helps clear blackheads and whiteheads.
Uploaded by: silverkeith on 07/09/2019

La Roche-Posay Effaclar Duo Acne Spot Treatment
Ingredients explained

What-it-does: anti-acne

The gold standard topical ingredient in treating acne today. There is no miracle cure for acne (we do really wish for one, *sigh*), but Benzoyl Peroxide (BP) is probably the closest thing we have. But, as usual, big effects come with big side effects, so we think BP is best used as a last resort (at least, in the topical treatment field). 

The good thing about BP is that it is amazingly effective against inflammatory-type acne. Not so much against blackheads or whiteheads, but against acne that is caused by the evil bacteria called Propionibacterium acnes (and that is most types of acne).  Apart from being antibacterial, it is also anti-inflammatory, keratolytic and wound-healing, all of which are properties that make it so darn effective against spots.

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Another big pro of BP is that there is no bacterial resistance to it, meaning if it works once it will continue to work. Antibiotics are also a common way to treat acne, but antibiotic-resistant P. acnes are increasing worldwide. BP will probably help you even if antibiotics have stopped working, and the two are also often combined for a more complex acne therapy. Btw, BP plays nice not only with antibiotics but also with retinoids

The side-effects part? BP works its antibacterial magic by being a powerful oxidizing agent, meaning it is a pro-oxidant. As in the opposite of an antioxidant. BP literally generates evil ROS (reactive oxygen species) in the skin that kills P. acnes but also harms the surrounding skin cells. Ongoing BP-use ages your skin, which is why, we say, use it as a last resort. If you do use BP, please also use a good sunscreen and a good antioxidant serum to apologise to your skin (btw, these things are useful in any case). Use the BP treatment at night and the antioxidant serum in the morning so that they do not cancel each other out.

Another side effect of BP is that it can be very skin drying. BP is an example where more is not better. In fact, it is equally effective at concentrations of 2.5, 5.0 and 10%, but the higher the concentration the more irritating and drying side effects occur. So using BP at 2.5% percent is the ideal amount. Another side effect which is good to know is that BP can bleach bedsheets and clothes. Be careful with your expensive satin bedsheets.

Overall, Benzoyl Peroxide is a uniquely effective topical acne treatment, but it comes at a price. Use it as a last resort and for good measure (and with plenty of moisturizers, sunscreen, and antioxidant serum). 

Also-called: Aqua | 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. 

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Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying. 

One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time. 

We don't have description for this ingredient yet.

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 at higher concentrations up to 20-40% (around 10% is a good usability-effectiveness sweet spot)
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as an emulsion stabilizer, solvent and a broad spectrum antimicrobial. According to manufacturer info, it's also a moisturizer and helps to make the product feel great on the skin. It works synergistically with preservatives and helps to improve water-resistance of sunscreens. 

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: viscosity controlling | Irritancy: 0 | Comedogenicity: 1

A big molecule created from repeated subunits (a polymer of acrylic acid) that magically converts a liquid into a nice gel formula.  It usually has to be neutralized with a base (such as sodium hydroxide) for the thickening to occur and it creates viscous, clear gels that also feel nice and non-tacky on the skin. No wonder, it is a very popular and common ingredient.

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

We don't have description for this ingredient yet.

What-it-does: buffering

It's a very alkaline stuff that helps to set the pH of the cosmetic formula to be just right. It's similar to the more often used sodium hydroxide and pretty much the same of what we wrote there applies here too. 

Also-called: Vitamin E Acetate | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 0

It’s the most commonly used version of pure vitamin E in cosmetics. You can read all about the pure form here. This one is the so-called esterified version. 

According to famous dermatologist, Leslie Baumann while tocopheryl acetate is more stable and has a longer shelf life, it’s also more poorly absorbed by the skin and may not have the same awesome photoprotective effects as pure Vit E. 

Though its long name does not reveal it, this polymer molecule (big molecule from repeated subunits or monomers) is a relative to the super common, water-loving thickener, Carbomer. Both of them are big molecules that contain acrylic acid units, but Acrylates/C10-30 Alkyl Acrylate Crosspolymer also contains some other monomers that are hydrophobic, i.e. water-hating. 

This means that our molecule is part water- and part oil-loving, so it not only works as a thickener but also as an emulsion stabilizer. It is very common in gel-type formulas that also contain an oil-phase as well as in cleansers as it also works with most cleansing agents (unlike a lot of other thickeners). 

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.

We don't have description for this ingredient yet.

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what‑it‑does anti-acne
The gold standard topical ingredient in treating acne today. It is uniquely effective in treating inflammatory type acne, but it comes at a price (pro-oxidant and skin drying). [more]
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 emollient | viscosity controlling
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 solvent | moisturizer/humectant
A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as an emulsion stabilizer, solvent, and a broad spectrum antimicrobial. [more]
what‑it‑does viscosity controlling
A white powdery thing that can mattify the skin and thicken up cosmetic products. [more]
what‑it‑does viscosity controlling
irritancy, com. 0, 1
A handy white powder that magically converts a liquid into a nice gel formula. [more]
what‑it‑does exfoliant
what‑it‑does buffering
It's a very alkaline stuff that helps to set the pH of the cosmetic formula to be just right. [more]
what‑it‑does antioxidant
irritancy, com. 0, 0
A form of vitamin E that works as an antioxidant. Compared to the pure form it's more stable, has longer shelf life, but it's also more poorly absorbed by the skin. [more]
what‑it‑does viscosity controlling
A common helper ingredient that stabilizes emulsions and helps to thicken up products. [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]