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rollover reaction 101 Custard Tart

101 Custard Tart

When color and care conspire, it creates the perfect combination for your everyday face base. Its breathable, lightweight formula delivers the ultimate triple threat—skin hydration, SPF protection, and buildable coverage.
Uploaded by: raiiin on

rollover reaction 101 Custard Tart
Ingredients explained

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. 

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).

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Anyway, it doesn't matter if it reflects or absorbs, Titanium Dioxide is a pretty awesome sunscreen agent for two main reasons: it gives a nice broad spectrum coverage and it's highly stable. Its protection is very good between 290 - 350 nm (UVB and UVA II range), and less good at 350-400 nm (UVA I) range. Regular sized Titanium Dioxide also has a great safety profile, it's non-irritating and is pretty much free from any health concerns (like estrogenic effect worries with some chemical filters).

The disadvantage of Titanium Dioxide is that it's not cosmetically elegant, meaning it's a white, "unspreadable" mess. Sunscreens containing Titanium Dioxide are often hard to spread on the skin and they leave a disturbing whitish tint. The cosmetic industry is, of course, really trying to solve this problem and the best solution so far is using nanoparticles. The itsy-bitsy Nano-sized particles improve both spreadability and reduce the whitish tint a lot, but unfortunately, it also introduces new health concerns. 

The main concern with nanoparticles is that they are so tiny that they are absorbed into the skin more than we want them (ideally sunscreen should remain on the surface of the skin). Once absorbed they might form unwanted complexes with proteins and they might promote the formation of evil free radicals. But do not panic, these are concerns under investigation. A 2009 review article about the safety of nanoparticles summarizes this, "to date, in-vivo and in-vitro studies have not demonstrated percutaneous penetration of nanosized particles in titanium dioxide and zinc oxide sunscreens". The English translation is, so far it looks like sunscreens with nanoparticles do stay on the surface of the skin where they should be.  

All in all, Titanium Dioxide is a famous sunscreen agent and for good reason, it gives broad spectrum UV protection (best at UVB and UVA II), it's highly stable, and it has a good safety profile. It's definitely one of the best UV-filter agents we have today, especially in the US where new-generation Tinosorb filters are not (yet) approved. 

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: 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).

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Regarding safety, there are also some concerns around Octinoxate. In vitro (made in the lab not on real people) and animal studies have shown that it may produce hormonal (estrogen-like) effects. Do not panic, the studies were not conducted under real life conditions on real human people, so it is probably over-cautious to avoid Octinoxate altogether. However, if you are pregnant or a small child (under 2 yrs. old), choose a physical (zinc oxide/titanium dioxide) or new-generation Tinosorb based sunscreen, just to be on the super-safe side. :) 

Overall, Ethylhexyl Methoxycinnamate is an old-school chemical sunscreen agent. There are plenty of better options for sun protection today, but it is considered "safe as used" (and sunscreens are pretty well regulated) and it is available worldwide (can be used up to 10% in the EU and up to 7.5% in the US).

What-it-does: emollient, solvent

A light-feeling, volatile (meaning it does not absorb into the skin but evaporates from it) silicone that gives skin a unique, silky and non-greasy feel. It has excellent spreading properties and leaves no oily residue or build-up. 

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

An odorless and colorless emollient ester (cetyl alcohol + ethylhexanoic acid) that gives a velvety and silky feel to the skin. It has great spreadability and a non-oily feel. It's a popular ingredient in makeup removers.

Also-called: Cetyl Dimethicone Copolyol | What-it-does: emulsifying, surfactant/cleansing

A silicone emulsifier that helps water and silicone oils to mix nicely together. 

What-it-does: emollient

A silicone fluid that gives a nonoily, easy to spread emolliency to the formulas. It is also used as a water repellent additive and to reduce the tackiness and stickiness of other ingredients. It also imparts gloss, softness and better manageability to hair.

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).

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. 

What-it-does: absorbent/mattifier

Porous spherical microbeads (tiny little balls) that can give an elegant silky texture to the products. They are also used to scatter light to reduce the look of fine lines on the skin, as well as to absorb excess oil and give a matt finish. 

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. 

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As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types). 

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: emulsifying

A silicone emulsifier that helps water and silicone oils to mix nicely together. It can also be used together with plant oil + silicone oil mixtures. 

Also-called: Epsom salt | What-it-does: viscosity controlling

A helper ingredient that is used as a bulking and viscosity controlling agent. It is also an emulsion stabilizer in water-in-oil emulsions, where water droplets are dispersed in the continuous oil phase and not the other way round.

It can also be used as a heat generating agent in water-less formulas as it has an instant heat-generating chemical reaction with water. 

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. 

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Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10). 

It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.

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. 

What-it-does: emollient

A solid silicone resin that creates a permeable film over the skin. It makes makeup formulas more long-lasting and can enhance the water resistance of sunscreens. It leaves a non-tacky film when dried. 

What-it-does: viscosity controlling

An organic derivative of hectorite clay, Disteardimonium Hectorite is used as a viscosity controller - it thickens up formulations to make them less runny.

It’s most popular use in cosmetics is in sunscreens, under the trademarked name Bentone 38 from Elementis. According to the manufacturer info, it is a real multi-tasker, including the ability to prevent pigments settling during storage, stabilizing a formula for longercreating a light and smooth skin feel and enhancing the water-resistance of sunscreen formulas
 

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.

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Other than that, Aluminum Hydroxide also often shows up in composite pigment technologies where it is used the other way around (as the base material and not as the coating material) and helps to achieve higher color coverage with less pigment

A clear, light yellow liquid that is used to coat pigments (such as inorganic sunscreen agents or colorants) in cosmetic products.  The coating helps to stabilize pigments in the formulas and also helps them to spread easily and evenly on the skin. 

Betaine - goodie
What-it-does: moisturizer/humectant

A sugar beet derived amino acid derivative with nice skin protection and moisturization properties. Betain's special thing is being an osmolyte, a molecule that helps to control cell-water balance.  It is also a natural osmoprotectant, meaning that it attracts water away from the protein surface and thus protects them from denaturation and increases their thermodynamic stability. 

It also gives sensorial benefits to the formula and when used in cleansers, it helps to make them milder and gentler. 

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).

What-it-does: preservative, deodorant

If you have spotted ethylhexylglycerin on the ingredient list, most probably you will see there also the current IT-preservative, phenoxyethanol. They are good friends because ethylhexylglycerin can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too.

Also, it's an effective deodorant and a medium spreading emollient

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.

What-it-does: solvent

A really multi-functional helper ingredient that can do several things in a skincare product: it can bring a soft and pleasant feel to the formula, it can act as a humectant and emollient, it can be a solvent for some other ingredients (for example it can help to stabilize perfumes in watery products) and it can also help to disperse pigments more evenly in makeup products. And that is still not all: it can also boost the antimicrobial activity of preservatives

What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0

It’s the - sodium form - cousin of the famous NMFhyaluronic acid (HA). If HA does not tell you anything we have a super detailed, geeky explanation about it here.  The TL; DR version of HA is that it's a huge polymer (big molecule from repeated subunits) found in the skin that acts as a sponge helping the skin to hold onto water, being plump and elastic. HA is famous for its crazy water holding capacity as it can bind up to 1000 times its own weight in water.

As far as skincare goes, sodium hyaluronate and hyaluronic acid are pretty much the same and the two names are used interchangeably. As cosmetic chemist kindofstephen writes on reddit  "sodium hyaluronate disassociates into hyaluronic acid molecule and a sodium atom in solution". 

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In spite of this, if you search for "hyaluronic acid vs sodium hyaluronate" you will find on multiple places that sodium hyaluronate is smaller and can penetrate the skin better. Chemically, this is definitely not true, as the two forms are almost the same, both are polymers and the subunits can be repeated in both forms as much as you like. (We also checked Prospector for sodium hyaluronate versions actually used in cosmetic products and found that the most common molecular weight was 1.5-1.8 million Da that absolutely counts as high molecular weight).

What seems to be a true difference, though, is that the salt form is more stable, easier to formulate and cheaper so it pops up more often on the ingredient lists. 

If you wanna become a real HA-and-the-skin expert you can read way more about the topic at hyaluronic acid (including penetration-questions, differences between high and low molecular weight versions and a bunch of references to scientific literature).

Allantoin - goodie
What-it-does: soothing | Irritancy: 0 | Comedogenicity: 0

Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. 

It's not only soothing but it' also skin-softening and protecting and can promote wound healing.

Caffeine - goodie
What-it-does: antioxidant, perfuming

Hello, our favorite molecule that helps us wake up in the morning and then keeps us going through the day. As a super well-known stimulant from coffee, tea and plenty of other soft drinks, Caffeine needs no introduction. So we will skip right to the part where we talk about what the hell it does in so-so many cosmetic products.

Looking at the research, we were surprised to find how versatile Caffeine is. It is a small, water-loving molecule with pretty good skin penetration abilties. Once in the skin, it has nice antioxidant properties, meaning that it reduces the formation of evil free radicals and it might even be useful in preventing UV-induced skin cancers. 

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A well-known thing about Caffeine is that it improves the microcirculation of the blood vessels. Though conventional wisdom and anecdotal evidence says that this property is helpful for dark under-eye circles and puffy eyes, we have to mention that the double-blind research we have found about a 3% caffeine gel concluded that "the overall efficacy of the selected caffeine gel in reducing puffy eyes was not significantly different from that of its gel base."  But you know, the proof is in the pudding.

Another thing Caffeine is used for in body care products is its anti-cellulite effects. In theory, it can speed up the lipolysis process (the "fat burning"  by our cells) and stimulate the draining lymph system that might lead to the improvement of cellulite. But here again, the evidence that it actually makes a measurable, let alone visible,  improvement on actual human beings is limited (we could find only some animal skin studies or caffeine being combined with other actives). 

Last, but not least, we have to write about caffeine and hair growth. The theory is that it can inhibit the activity of the 5-α-reductase enzyme that plays an important role in hair loss and allows a renewed growth phase of the hair. We have found some recent and promising research to back this up. A 2017 study compared a 0.2% caffeine liquid with a 5% Minoxidil  (an FDA approved active to treat baldness) solution and found that  "a caffeine-based topical liquid should be considered as not inferior to minoxidil 5% solution in men with androgenetic alopecia", or English translation means that the caffeine liquid was pretty much as good as the FDA-approved Minoxidil stuff. Not bad!

Overall, we think that caffeine is a very versatile and biologically active ingredient. Even though some of its effects are more hyped up than backed up, it is still a nice to have on many ingredient lists. 

Also-called: Iron Oxide Yellow | What-it-does: colorant | Irritancy: 0 | Comedogenicity: 0

Yellow Iron Oxide is the super common inorganic (as in no carbon atom in the molecule) pigment that gives the yellow tones in your foundation. Blended with red and black iron oxides, it is essential in all "flesh-toned" makeup products. 

Chemically speaking, it is hydrated iron III oxide and depending on the conditions of manufacture, it can range from a light lemon to an orange-yellow shade.  

Also-called: Iron Oxide Red | What-it-does: colorant | Irritancy: 0 | Comedogenicity: 0

Red Iron Oxide is the super common pigment that gives the familiar, "rust" red color. It is also the one that gives the pink tones in your foundation. Chemically speaking, it is iron III oxide (Fe2O3). 

Also-called: Iron Oxide Black | What-it-does: colorant | Irritancy: 0 | Comedogenicity: 0

Black Iron Oxide is the super common inorganic (as in no carbon atom in the molecule) pigment that controls the darkness of your foundation or gives the blackness to your mascara. Blended with red and black iron oxides, it is essential in all "flesh-toned" makeup products.

Chemically speaking, it is a mixture of iron II and iron III oxide. Btw, this guy, unlike the yellow and red pigments, is magnetic. 

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 | 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 | 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
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 emollient | solvent
A light-feeling, volatile silicone that gives skin a unique, silky and non-greasy feel. It has excellent spreading properties and leaves no oily residue or build-up. 
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
An odorless and colorless emollient ester that gives a velvety and silky feel to the skin. [more]
what‑it‑does emulsifying | surfactant/cleansing
A silicone emulsifier that helps water and silicone oils to mix nicely together. 
what‑it‑does emollient
A silicone fluid that gives a nonoily, easy to spread emolliency to the formulas. [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 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]
Porous spherical microbeads that can give an elegant silky texture to the products. They are also used to scatter light to reduce the look of fine lines on the skin, as well as to absorb excess oil and give a matt finish. 
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 viscosity controlling
A white powdery thing that can mattify the skin and thicken up cosmetic products. [more]
what‑it‑does emulsifying
A silicone emulsifier that helps water and silicone oils to mix nicely together. [more]
what‑it‑does viscosity controlling
A helper ingredient that is used as a bulking and viscosity controlling agent. It is also an emulsion stabilizer in water-in-oil emulsions, where water droplets are dispersed in the continuous oil phase and not the other way round. It can also be used as a heat generating agent in water-less formulas as it has an instant heat-generating chemical reaction with water. [more]
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 viscosity controlling
A white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. [more]
what‑it‑does emollient
A solid silicone resin that creates a permeable film over the skin. It makes makeup formulas more long-lasting and can enhance the water resistance of sunscreens. It leaves a non-tacky film when dried. 
what‑it‑does viscosity controlling
An organic derivative of hectorite clay, Disteardimonium Hectorite is used as a viscosity controller - it thickens up formulations to make them less runny.It’s most popular use in cosmetics is in sunscreens, under the trademarked name Bentone 38 from Elementis. [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]
A clear, light yellow liquid that is used to coat pigments (such as inorganic sunscreen agents or colorants) in cosmetic products.  [more]
what‑it‑does moisturizer/humectant
A sugar beet derived amino acid derivative with nice skin protection and moisturization properties. Its special thing is being an osmolyte, a molecule that helps to control cell-water balance.  [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]
what‑it‑does preservative
It can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too. [more]
what‑it‑does chelating | viscosity controlling
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 solvent
A multi-functional helper ingredient that acts as a humectant and emollient. It's also a solvent and can boost the effectiveness of preservatives. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
It's the salt form of famous humectant and natural moisturizing factor, hyaluronic acid. It can bind huge amounts of water and it's pretty much the current IT-moisturizer. [more]
what‑it‑does soothing
irritancy, com. 0, 0
Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. It's not only soothing but it' [more]
what‑it‑does antioxidant | perfuming
The well-known stimulant from coffee. It has nice antioxidant properties and can improve the microcirculation. Might be helpful for dark circles, puffy eyes, as well as cellulite and hair loss. [more]
what‑it‑does colorant
irritancy, com. 0, 0
CI 77492 or Iron Oxide is a common colorant with the color yellow.  [more]
what‑it‑does colorant
irritancy, com. 0, 0
Iron Oxide - a super common colorant with the color red.  [more]
what‑it‑does colorant
irritancy, com. 0, 0
CI 77499 or Iron Oxide is a super common colorant with the color black.  [more]