Follow us on our new Insta page »
ACM Laboratoire Duolys Spf 50+

Duolys Spf 50+

Duolys, anti-aging sunscreen cream spf 50+
Uploaded by: andreeam on

ACM Laboratoire Duolys Spf 50+
Ingredients explained

Also-called: 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: 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.

Also-called: Octinoxate, Octyl Methoxycinnamate | What-it-does: sunscreen | Irritancy: 0 | Comedogenicity: 0

A clear, oil-soluble, "cosmetically-elegant" liquid that is the most commonly used chemical sunscreen. It absorbs UVB radiation (at wavelengths: 280-320 nm) with a peak protection at 310nm. 

It only protects against UVB and not UVA rays (the 320-400 nm range) – so always choose products that contain other sunscreens too. It is not very stable either, when exposed to sunlight, it kind of breaks down and loses its effectiveness (not instantly, but over time - it loses 10% of its SPF protection ability within 35 mins). To make it more stable it can be - and should be - combined with other sunscreen agents to give stable and broad-spectrum protection (the new generation sunscreen agent, Tinosorb S is a particularly good one for that).

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.

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).

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 >>

What-it-does: emollient, solvent

A super commonly used 5 unit long, cyclic structured silicone that is water-thin and does not stay on the skin but evaporates from it (called volatile silicone). Similar to other silicones, it gives skin and hair a silky, smooth feel

It's often combined with the non-volatile (i.e. stays on the skin) dimethicone as the two together form a water-resistant, breathable protective barrier on the skin without a negative tacky feel.

Also-called: Tinosorb S, Bemotrizinol | What-it-does: sunscreen

Its INCI name is a bit of a mouthful, but Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine is worth recognizing it as it is one of the best sunscreen agents known today. Unfortunately, it's not FDA-approved so you will not find it in sunscreens coming from the US (not because it's not good, but because US regulations make it impossible for newer sunscreen agents to get approved), but it is widely available in other parts of the world like Europe, Australia or Asia. 

It is a broad-spectrum (covers the whole UVB and UVA range, 280-400 nm) chemical sunscreen agent with peak protections at about 310 and 345 nm and unlike older UV filters, it's very photostable. It hardly deteriorates in the presence of UV light and it's also useful in stabilizing other less stable sunscreen agents, like the famous UVA protector, avobenzone.

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: sunscreen, colorant

Titanium Dioxide is one of the two members of the elite sunscreen group called physical sunscreens (or inorganic sunscreens if you’re a science geek and want to be precise).

Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).

What-it-does: emollient, emulsifying | Irritancy: 0 | Comedogenicity: 1-2

A super common, waxy, white, solid stuff that helps water and oil to mix together, gives body to creams and leaves the skin feeling soft and smooth.

Chemically speaking, it is the attachment of a glycerin molecule to the fatty acid called stearic acid. It can be produced from most vegetable oils (in oils three fatty acid molecules are attached to glycerin instead of just one like here) in a pretty simple, "green" process that is similar to soap making. It's readily biodegradable.

What-it-does: surfactant/cleansing, emulsifying | Irritancy: 0 | Comedogenicity: 0

A very common water-loving surfactant and emulsifier that helps to keep water and oil mixed nicely together. 

It's often paired with glyceryl stearate - the two together form a super effective emulsifier duo that's salt and acid tolerant and works over a wide pH range. It also gives a "pleasing product aesthetics", so no wonder it's popular.

Also-called: Uvinul T 150, Octyltriazone | What-it-does: sunscreen

Ethylhexyl Triazone is a new generation, chemical sunscreen (not available in the US due to impossible FDA regulations) that gives the highest photo-stable absorption of all available UVB filters today. It protects in the UVB range (280-320nm) with a peak protection of 314nm. It is an oil soluble, odorless, colorless powder that works well in fragrance-free formulas. It can be used up to 5% worldwide except for the US and Canada.

What-it-does: surfactant/cleansing

A vegetable origin (coconut/palm kernel oil, glucose) cleansing agent that gives moderate to high stable foam. It's also biodegradable and mild to the skin.

Also-called: Form of Vitamin C | What-it-does: antioxidant, skin brightening

A form of skincare superstar, vitamin C. If you do not know why vitamin C is such a big deal in skincare, we have a really detailed, geeky description that's good to read. :) 

So now you know that because pure vitamin C is such a diva (very unstable and hard to formulate) the cosmetic industry is trying to come up with some derivatives that have the badass anti-aging properties of vitamin C (antioxidant protection + collagen boosting + fading hyperpigmentation) but without the disadvantages. This is a hard task, and there is not yet a derivative that is really proven to be better in every aspect, but Ascorbyl Glucoside is one of the best options when it comes to vitamin C derivatives. Let's see why:

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

What-it-does: preservative

It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.

It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic. 

A little helper ingredient that works as a preservative. It works against bacteria and some species of fungi and yeast. It's often combined with IT-preservative, phenoxyethanol.

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). 

Officially, CosIng (the official EU ingredient database) lists Aluminum Hydroxide 's functions as opacifying (making the product white and non-transparent), as well as emollient and skin protectant.

However, with a little bit of digging, it turns out Aluminum Hyroxide often moonlights as a protective coating for UV filter superstar Titanium Dioxide. Specifically, it protects our skin from the harmful effects of nasty Reactive Oxygen Species (free radicals derived from oxygen such as Superoxide and Hydrogen Peroxide) generated when Titanium Dioxide is exposed to UV light. Btw, chlorine in swimming pool water depletes this protective coating, so one more reason to reapply your sunscreen after a dip in the pool on holiday.

What-it-does: viscosity controlling

Polyethylene is the most common plastic in the world. It is a super versatile polymer (molecule from repeated subunits) and when it comes to cosmetics, it is often referred to as microbeads. Well, it used to be referred to as microbeads, as it was banned in 2015 in the " Microbead-Free Waters Act" due to the small plastic spheres accumulating in the waters and looking like food to fish. Well done by Obama. 

But being versatile means that polyethylene does not only come as scrub particles but also as a white wax. In its wax-form, it is still well, alive and pretty popular. It thickens up water-free formulas, increases hardness and raises the melting point of emulsions and water-less balms. It is particularly common in cleansing balms and stick-type makeup products due to its ability to add body, hardness and slip to these formulas. 

What-it-does: emollient, viscosity controlling | Irritancy: 0 | Comedogenicity: 2-3

A common multi-tasker fatty acid. It makes your skin feel nice and smooth (emollient), gives body to cream type products and helps to stabilize water and oil mixes (aka emulsions).

A type of silicone elastomer (rubber-like material with both viscosity and elasticity) whose major function is forming a nice film on the skin.

It is also cosmetically very elegant with a non-tacky, non-oily and smooth skin feel. It also works as a stable delivery system of active materials, has sebum absorption and control properties and upon application, it transforms into a matte appearance with a powdery after feel.

What-it-does: preservative

It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It’s not a strong one and doesn’t really work against bacteria, but more against mold and yeast. To do that it has to break down to its active form, sorbic acid. For that to happen, there has to be water in the product and the right pH value (pH 3-4). 

But even if everything is right, it’s not enough on its own. If you see potassium sorbate you should see some other preservative next to it too.

What-it-does: emollient

We don't have description for this ingredient yet.

Tocopherol - goodie
Also-called: Vitamin E | What-it-does: antioxidant | Irritancy: 0-3 | Comedogenicity: 0-3
  • Primary fat-soluble antioxidant in our skin
  • Significant photoprotection against UVB rays
  • Vit C + Vit E work in synergy and provide great photoprotection
  • Has emollient properties
  • Easy to formulate, stable and relatively inexpensive
Read all the geeky details about Tocopherol here >>

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.

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: buffering

Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA. 

So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh. 

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 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 sunscreen
irritancy, com. 0, 0
Octinoxate - an old-school chemical sunscreen that absorbs UVB radiation (wavelengths: 280-320 nm). Not photostable and does not protect against UVA. [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 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 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 emollient | solvent
It's a super commonly used water-thin volatile silicone that gives skin and hair a silky, smooth feel.  [more]
what‑it‑does sunscreen
Tinosorb S - a new generation, broad-spectrum and very photostable sunscreen agent with great safety profile. [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 sunscreen | colorant
A physical/inorganic sunscreen with pretty broad spectrum (UVB and UVA II, less good at UVA I) protection and good stability. Might leave some whitish tint on the skin, though. [more]
what‑it‑does emollient | emulsifying
irritancy, com. 0, 1-2
Waxy, white, solid stuff that helps water and oil to mix together and leaves the skin feeling soft and smooth. [more]
what‑it‑does surfactant/cleansing | emulsifying
irritancy, com. 0, 0
A commonly used water-soluble surfactant and emulsifier. [more]
what‑it‑does sunscreen
Uvinul T 150 - A new generation, chemical sunscreen (not available in the US due to impossible FDA regulations) that gives the highest photo-stable absorption of all available UVB filters today. [more]
what‑it‑does surfactant/cleansing
A vegetable origin (coconut/palm kernel oil, glucose) cleansing agent that gives moderate to high stable foam. It's also biodegradable and mild to the skin.
what‑it‑does antioxidant | skin brightening
A stable and easy to formulate form of skincare superstar, vitamin C. In-vitro studies show that it shows all the three anti-aging benefits (antioxidant protection + collagen boosting + fading hyperpigmentation) that pure vitamin C does. [more]
what‑it‑does emollient | emulsifying | surfactant/cleansing | viscosity controlling
what‑it‑does preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]
what‑it‑does preservative | antimicrobial/antibacterial
A little helper ingredient that works as a preservative. It works against bacteria and some species of fungi and yeast. [more]
what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does emollient | moisturizer/humectant | viscosity controlling
Officially, CosIng (the official EU ingredient database) lists Aluminum Hydroxide 's functions as opacifying (making the product white and non-transparent), as well as emollient and skin protectant. However, with a little bit of digging, it turns out Aluminum Hyroxide often moonlights as a protective coating for UV filter superstar Titanium Dioxide. [more]
what‑it‑does viscosity controlling
The common plastic molecule that is used as a white wax to give hardness and slip to the formulas. It used to be used as microbeads as well but was banned in 2015 due to environmental reasons. [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 0, 2-3
A common multi-tasker fatty acid that works as an emollient, thickener and emulsion stabilizer. [more]
A type of silicone elastomer (rubber-like material with both viscosity and elasticity) whose major function is forming a nice film on the skin. [more]
what‑it‑does preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]
what‑it‑does emollient
what‑it‑does antioxidant
irritancy, com. 0-3, 0-3
Pure Vitamin E. Great antioxidant that gives significant photoprotection against UVB rays. Works in synergy with Vitamin C. [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 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 buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [more]