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Rimmel Long Lasting Finish 25 Hr Foundation

Long Lasting Finish 25 Hr Foundation

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Highlights

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Alcohol Free

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Other Ingredients

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Ingredient name what-it-does irr., com. ID-Rating
Aqua/Water/Eau solvent
Cyclopentasiloxane emollient, solvent
Titanium Dioxide sunscreen, colorant goodie
Butylene Glycol moisturizer/​humectant, solvent, viscosity controlling 0, 1
Cetyl PEG/PPG-10/1 Dimethicone emulsifying, surfactant/​cleansing
Ethylhexyl Methoxycinnamate sunscreen 0, 0
Talc abrasive/​scrub 0, 1
Trimethylsiloxysilicate emollient
Sodium PCA skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Silica Silylate viscosity controlling, emollient
C12-15 Alkyl Ethylhexanoate emollient
Magnesium Sulfate viscosity controlling
Zinc Stearate colorant, viscosity controlling 0, 0
Dimethicone/Vinyl Dimethicone Crosspolymer viscosity controlling
Acrylates/C12-22 Alkyl Methacrylate Copolymer
Bis-PEG/PPG-14/14 Dimethicone emollient, emulsifying, surfactant/​cleansing
Amodimethicone emollient
Laureth-7 emulsifying, surfactant/​cleansing
Lecithin emollient, emulsifying goodie
Tribehenin emollient
Disteardimonium Hectorite viscosity controlling
Phenoxyethanol preservative
Trihydroxystearin viscosity controlling
Chlorphenesin preservative, antimicrobial/​antibacterial
Dimethiconol emollient, moisturizer/​humectant
Triethoxycaprylylsilane
Xanthan Gum viscosity controlling, emulsifying, surfactant/​cleansing
Parfum/Fragrance perfuming icky
Pentylene Glycol solvent, moisturizer/​humectant
Tocopheryl Acetate antioxidant 0, 0
Propylene Carbonate solvent, viscosity controlling
Hydroxyethylcellulose viscosity controlling
Glycerin skin-identical ingredient, moisturizer/​humectant 0, 0 superstar
Citric Acid buffering
Fructose moisturizer/​humectant goodie
Sodium Hydroxide buffering
Urea skin-identical ingredient, moisturizer/​humectant goodie
Laureth-4 emulsifying, surfactant/​cleansing 4, 5
Hexyl Cinnamal perfuming icky
Limonene perfuming, solvent icky
Butylphenyl Methylpropional perfuming icky
Allantoin soothing 0, 0 goodie
Maltose moisturizer/​humectant
Sodium Chloride viscosity controlling
Sodium Lactate buffering, moisturizer/​humectant goodie
Sodium Sulfate viscosity controlling
Trehalose moisturizer/​humectant goodie
Benzyl Salicylate perfuming icky
Linalool perfuming icky
Geraniol perfuming icky
BHT antioxidant, preservative
Citronellol perfuming icky
Alpha-Isomethyl Ionone perfuming icky
Glucose moisturizer/​humectant goodie
Sodium Hyaluronate skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate antioxidant, preservative
Iron Oxides (Ci 77491, Ci 77492, Ci 77499)] colorant 0, 0

Rimmel Long Lasting Finish 25 Hr Foundation
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. 

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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: 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.

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: moisturizer/humectant, solvent, viscosity controlling | Irritancy: 0 | Comedogenicity: 1

Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.  

BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.

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It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive. 

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

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

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: absorbent/mattifier, abrasive/scrub | Irritancy: 0 | Comedogenicity: 1

Talc is the major component of most powder makeup products (think face powder, eyeshadows, and blushers) that usually contain it up to 70%. Its two winning properties that make it very suitable for this role is its outstanding spreadability for a smooth application and its low covering power, aka translucency to avoid clown-like effects.

Chemically speaking, it is a clay mineral (hydrated magnesium silicate) that is mined in several countries. The drawback of mined minerals is potential impurities and the version used in cosmetics has to be white (not gray like cheaper grades), free from asbestos, sterilized and have thin plates for a maximum slip. 

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. 

Sodium PCA - goodie
Also-called: Sodium Pyrrolidone Carboxylic Acid | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0

PCA stands for Pyrrolidone Carboxylic Acid and though it might not sound like it, it is a thing that can be found naturally in our skin. The sodium salt form of PCA is an important skin-identical ingredient and great natural moisturizer that helps the skin to hold onto water and stay nicely hydrated. 

A handy white powder that likes to absorb oily things. It has great oil and sebum absorption (aka mattifying) abilities and can also act as a thickening agent in the oil phase of a formula.

What-it-does: emollient

We don't have description for this ingredient yet.

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: colorant, viscosity controlling | Irritancy: 0 | Comedogenicity: 0

Zinc Stearate is probably the most commonly used binding agent in powder makeup products such as face powders or eyeshadows. It gives very good adherence qualities meaning it helps powders to stick together in the pan and to stick to the skin on application. It is typically used at 3-10%, too much of it though can cause lumpiness or greasiness on the skin.

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. 

Acrylates/C12-22 Alkyl Methacrylate Copolymer is a big molecule created from repeating subunits (aka polymer) used as a film-former. It is great at improving the water and wear resistance of sunscreens and makeup products.

A light and silky, silicone-based emulsifier that helps water and silicone oils to mix nicely together. It is water-soluble and it can impart lubricity and a pleasant skin feel.

What-it-does: emollient

A modified dimethicone-type silicone molecule that also contains amino-groups. Having amino-groups means that Amodimethicone also has Nitrogen in its molecule that likes to have a positive charge. Positively charged (or quaternised) molecules are substantive to skin and hair as those are negatively charged surfaces and are excellent film formers. Amodiemthcone is no exception and it is especially recommended for hair-care products for its long-lasting hair conditioning benefits.

A not-very-interesting helper ingredient that is used as an emulsifier and/or surfactant. Comes from a coconut oil derived fatty alcohol, lauryl alcohol.

Lecithin - goodie
What-it-does: emollient, emulsifying

A very common ingredient that can be found in all cell membranes. In cosmetics it's quite the multi-tasker: it's an emollient and water-binding ingredient but it's also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes

What-it-does: emollient

It's the triglyceride of behenic acid that works as a thickening or gelling agent, as a compacting agent for pressed powders, and improves heat stability of emulsions. 

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
 

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 hydrogenated castor oil derivative that is used as an oil gelling agent. It can thicken up both oils as well as silicones. 

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.

A thick, high molecular weight silicone that is usually diluted in another, lighter silicone fluid (like dimethicone or cyclopentasiloxane). The dimethiconol containing silicone blends leave a silky smooth, non-greasy film on the skin.

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. 

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). 

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.  

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Also, if your skin is sensitive, fragrance is again not your best friend. It’s the number one cause of contact allergy to cosmetics. It’s definitely a smart thing to avoid with sensitive skin (and fragrance of any type - natural is just as allergic as synthetic, if not worse!). 

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. 

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. 

We don't have description for this ingredient yet.

Also-called: HEC | What-it-does: viscosity controlling, emulsion stabilising

A nice little helper ingredient that can thicken up cosmetic products and create beautiful gel formulas. It's derived from cellulose, the major component of the cell wall of green plants. It is compatible with most co-ingredients and gives a very good slip to the formulas. 

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: 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. 

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There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin. 

But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation. 

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

Fancy name for fruit sugar. It has nice water-binding properties and helps to keep skin hydrated

Also-called: lye | What-it-does: buffering

The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right. 

For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.  

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BTW, lye is not something new. It was already used by ancient Egyptians to help oil and fat magically turn into something else. Can you guess what? Yes, it’s soap. It still often shows up in the ingredient list of soaps and other cleansers.

Sodium hydroxide in itself is a potent skin irritant, but once it's reacted (as it is usually in skin care products, like exfoliants) it is totally harmless.

Urea - goodie
Also-called: Carbamide | What-it-does: skin-identical ingredient, moisturizer/humectant

Yes, it's the thing that can be found naturally in pee. And in the skin. It is an awesome natural moisturizing factor, aka NMF.  NMFs are important components that help the skin to hold onto water and keep it plump, elastic and hydrated. Urea makes up about 7% of NMFs next to other things such as amino acids (40%), PCA (12%) or Lactate (12%).

What makes urea special, is that it is not only a simple moisturizer, but it is thought to be a "small-molecule regulator of epidermal structure and function" meaning that it has a bunch of extra biological activities. It acts as a mild keratolytic agent (some of its moisturizing action is thought to come from urea's ability to break down bonds in the protein called filaggrin and thus freeing up amino acids in the skin), enhances antimicrobial peptide expression and improves skin barrier function

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Being a mild keratolytic agent and strong moisturizer means that high-percentage (10-40%) urea treatments are found effective in a bunch of skin disorders connected to excessive dryness and malfunctioning skin barrier such as ichthyosis, xerosis, psoriasis, eczema and seborrheic dermatitis.  

Overall, just like glycerin, urea is a real oldie but a goodie, a nice ingredient in any moisturizer.

What-it-does: emulsifying, surfactant/cleansing | Irritancy: 4 | Comedogenicity: 5

We don't have description for this ingredient yet.

What-it-does: perfuming

A common fragrance ingredient that smells like jasmine. It is one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. Best to avoid if your skin is sensitive.

Limonene - icky
What-it-does: perfuming, solvent, deodorant

A super common and cheap fragrance ingredient. It's in many plants, e.g. rosemary, eucalyptus, lavender, lemongrass, peppermint and it's the main component (about 50-90%) of the peel oil of citrus fruits.

It does smell nice but the problem is that it oxidizes on air exposure and the resulting stuff is not good for the skin. Oxidized limonene can cause allergic contact dermatitis and counts as a frequent skin sensitizer

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Limonene's nr1 function is definitely being a fragrance component, but there are several studies showing that it's also a penetration enhancer, mainly for oil-loving components.

All in all, limonene has some pros and cons, but - especially if your skin is sensitive - the cons probably outweigh the pros.  

Also-called: Lilial | What-it-does: perfuming

A common fragrance ingredient that has a nice floral scent and also goes by the name Lilial. It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential. Best to avoid if your skin is sensitive. 

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.

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

Also-called: Salt | What-it-does: viscosity controlling

Sodium chloride is the fancy name of salt. Normal, everyday table salt

If (similar to us) you are in the weird habit of reading the label on your shower gel while taking a shower, you might have noticed that sodium chloride is almost always on the ingredient list. The reason for this is that salt acts as a fantastic thickener in cleansing formulas created with ionic cleansing agents (aka surfactants) such as Sodium Laureth Sulfate. A couple of percents (typically 1-3%) turns a runny surfactant solution into a nice gel texture.

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If you are into chemistry (if not, we understand, just skip this paragraph), the reason is that electrolytes (you know, the Na+ and Cl- ions) screen the electrostatic repulsion between the head groups of ionic surfactants and thus support the formation of long shaped micelles (instead of spherical ones) that entangle like spaghetti, and viola, a gel is formed. However, too much of it causes the phenomenon called "salting out", and the surfactant solution goes runny again. 

Other than that, salt also works as an emulsion stabilizer in water-in-oil emulsions, that is when water droplets are dispersed in the outer oil (or silicone) phase. And last but not least, when salt is right at the first spot of the ingredient list (and is not dissolved), the product is usually a body scrub where salt is the physical exfoliating agent

The sodium salt of lactic acid. It's a great skin moisturizer and also used to regulate the pH value of the cosmetic formula. It's a natural ingredient approved by both ECOCERT and COSMOS.

What-it-does: viscosity controlling

We don't have description for this ingredient yet.

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

A type of sugar that has water-binding properties and helps to keep your skin hydrated

What-it-does: perfuming

It’s a common fragrance ingredient that has a light floral smell.  It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential. Best to avoid if your skin is sensitive.

Linalool - icky
What-it-does: perfuming, deodorant

Linalool is a super common fragrance ingredient. It’s kind of everywhere - both in plants and in cosmetic products. It’s part of 200 natural oils including lavender, ylang-ylang, bergamot, jasmine, geranium and it can be found in 90-95% of prestige perfumes on the market. 

The problem with linalool is, that just like limonene it oxidises on air exposure and becomes allergenic. That’s why a product containing linalool that has been opened for several months is more likely to be allergenic than a fresh one.

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A study made in the UK with 483 people tested the allergic reaction to 3% oxidised linalool and 2.3% had positive test results. 

Geraniol - icky
What-it-does: perfuming

Geraniol is a common fragrance ingredient. It smells like rose and can be found in rose oil or in small quantities in geranium, lemon and many other essential oils. 

Just like other similar fragrance ingredients (like linalool and limonene) geraniol also oxidises on air exposure and becomes allergenic. Best to avoid if you have sensitive skin.

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.

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As for cosmetics, the CIR (Cosmetic Ingredient Review) concluded that the amount of BHT used in cosmetic products is low (usually around 0.01-0.1%),  it does not penetrate skin far enough to be absorbed into the bloodstream and it is safe to use in cosmetics.

What-it-does: perfuming

Citronellol is a very common fragrance ingredient with a nice rose-like odor. In the UK, it’s actually the third most often listed perfume on the ingredient lists. 

It can be naturally found in geranium oil (about 30%) or rose oil (about 25%). 

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As with all fragrance ingredients, citronellol can also cause allergic contact dermatitis and should be avoided if you have perfume allergy. In a 2001 worldwide study with 178 people with known sensitization to fragrances citronellol tested positive in 5.6% of the cases.

There is no known anti-aging or positive skin benefits of the ingredient. It’s in our products to make it smell nice. 

What-it-does: perfuming

It’s a common fragrance ingredient that is one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential. Best to avoid if your skin is sensitive.

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

A fancy name for sugar. Luckily when you put it on your skin it's good for you not like when you eat it. :) It has water-binding properties, which means that it helps to keep your skin nice and hydrated

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).

Also-called: Tinogard TT | What-it-does: antioxidant, preservative

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate is an antioxidant molecule used in small amounts (less than 0.8%) to help products stay nice longer. More specifically, it is great at preventing discoloration or other types of oxidative degradation. It is a trendy alternative to often bad-mouthed synthetic antioxidant and stabilizer, BHT

Also-called: Ci 77491/77492/77499;Iron Oxides | What-it-does: colorant | Irritancy: 0 | Comedogenicity: 0

A bit of a sloppy ingredient name as it covers not one but three pigments: red, yellow and black iron oxide.

The trio is invaluable for "skin-colored" makeup products  (think your foundation and pressed powder) as blending these three shades carefully can produce almost any shade of natural-looking flesh tones. 

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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
It's a super commonly used water-thin volatile silicone that gives skin and hair a silky, smooth feel.  [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 moisturizer/humectant | solvent | viscosity controlling
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An often used glycol that works as a solvent, humectant, penetration enhancer and also gives a good slip to the products. [more]
what‑it‑does emulsifying | surfactant/cleansing
A silicone emulsifier that helps water and silicone oils to mix nicely together. 
what‑it‑does sunscreen
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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 abrasive/scrub
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Talc is the major component of most powder makeup products (think face powder, eyeshadows, and blushers) that usually contain it up to 70%. Its two winning properties that make it very suitable for this role is its outstanding spreadability for a smooth application and its low covering power, aka translucency to avoid clown-like effects. [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 skin-identical ingredient | moisturizer/humectant
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It's an important skin-identical ingredient and great natural moisturizer that helps the skin to hold onto water and stay nicely hydrated. [more]
what‑it‑does viscosity controlling | emollient
A handy white powder that likes to absorb oily things. It has great oil and sebum absorption (aka mattifying) abilities and can also act as a thickening agent in the oil phase of a formula.
what‑it‑does emollient
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 colorant | viscosity controlling
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Zinc Stearate is probably the most commonly used binding agent in powder makeup products such as face powders or eyeshadows. It gives very good adherence qualities meaning it helps powders to stick together in the pan and to stick to the skin on application. [more]
what‑it‑does viscosity controlling
A white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. [more]
Acrylates/C12-22 Alkyl Methacrylate Copolymer is a big molecule created from repeating subunits (aka polymer) used as a film-former. It is great at improving the water and wear resistance of sunscreens and makeup products. [more]
what‑it‑does emollient | emulsifying | surfactant/cleansing
A light and silky, silicone-based emulsifier that helps water and silicone oils to mix nicely together. [more]
what‑it‑does emollient
A modified dimethicone-type silicone molecule that also contains amino-groups. Having amino-groups means that Amodimethicone also has Nitrogen in its molecule that likes to have a positive charge. [more]
what‑it‑does emulsifying | surfactant/cleansing
A not-very-interesting helper ingredient that is used as an emulsifier and/or surfactant. Comes from a coconut oil derived fatty alcohol, lauryl alcohol. [more]
what‑it‑does emollient | emulsifying
It's quite the multi-tasker: an emollient and water-binding ingredient but also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes.  [more]
what‑it‑does emollient
thickening/gelling agent, as a compacting agent for pressed powders (ATO grade), and improves heat stability of emulsions.
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 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 hydrogenated castor oil derivative that is used as an oil gelling agent. It can thicken up both oils as well as silicones.  [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 emollient | moisturizer/humectant
A thick, high molecular weight silicone that is usually diluted in a lighter silicone fluid. The dimethiconol containing silicone blends leave a silky smooth, non-greasy film on the skin. [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 viscosity controlling | emulsifying | surfactant/cleansing
A super commonly used thickener and emulsion stabilizer. [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]
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 antioxidant
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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 solvent | viscosity controlling
what‑it‑does viscosity controlling
A nice little helper ingredient that can thicken up cosmetic products and create beautiful gel formulas. It's derived from cellulose, the major component of the cell wall of green plants. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
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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 buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [more]
what‑it‑does moisturizer/humectant
Fancy name for fruit sugar. It has nice water-binding properties and helps to keep skin hydrated. 
what‑it‑does buffering
Lye - A solid white stuff that’s very alkaline and used in small amount to adjust the pH of the product.  [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
The thing in the pee that is also a natural moisturizing factor (NMF) with mild keratolytic and strong skin moisturizing superpowers. [more]
what‑it‑does emulsifying | surfactant/cleansing
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what‑it‑does perfuming
A common fragrance ingredient that smells like jasmine. It is one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. [more]
what‑it‑does perfuming | solvent
A super common fragrance ingredient found naturally in many plants including citrus peel oils, rosemary or lavender. It autoxidizes on air exposure and counts as a common skin sensitizer. [more]
what‑it‑does perfuming
A common fragrance ingredient that has a nice floral scent and also goes by the name Lilial. It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” [more]
what‑it‑does soothing
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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 moisturizer/humectant
what‑it‑does viscosity controlling
Sodium chloride is the fancy name of salt. Normal, everyday table salt.  If (similar to us) you are in the weird habit of reading the label on your shower gel while taking a shower, you might have noticed that sodium chloride is almost always on the ingredient list. [more]
what‑it‑does buffering | moisturizer/humectant
The sodium salt of lactic acid. It's a great skin moisturizer and also used to regulate the pH value of the cosmetic formula. [more]
what‑it‑does viscosity controlling
what‑it‑does moisturizer/humectant
A type of sugar that has water-binding properties and helps to keep your skin hydrated. 
what‑it‑does perfuming
It’s a common fragrance ingredient that has a light floral smell.  It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” [more]
what‑it‑does perfuming
A super common fragrance ingredient that can be found among others in lavender, ylang-ylang, bergamot or jasmine. The downside of it is that it oxidises on air exposure and might become allergenic. [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like rose and can be found in rose oil. [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 perfuming
A common fragrance ingredient with a nice rose-like smell. [more]
what‑it‑does perfuming
It’s a common fragrance ingredient that is one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” [more]
what‑it‑does moisturizer/humectant
Sugar - as a skincare ingredient it has water-binding properties, which means that it helps to keep your skin nice and hydrated.  [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 antioxidant | preservative
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate is an antioxidant molecule used in small amounts (less than 0.8%) to help products stay nice longer. More specifically, it is great at preventing discoloration or other types of oxidative degradation. [more]
what‑it‑does colorant
irritancy, com. 0, 0
A mix of red, yellow and black iron oxide. [more]