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Kiehl’s Facial Fuel Eye De-Puffer

Facial Fuel Eye De-Puffer

"A lightweight, cooling eye stick that minimizes puffiness"
Uploaded by: andreas on 15/04/2019

Kiehl’s Facial Fuel Eye De-Puffer
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: moisturizer/humectant, solvent | 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. 

Bis-PEG-18 Methyl Ether Dimethyl Silane is a silicone that is water dispersible (as opposed to most other silicones that are usually oil dispersible). It makes the skin smooth and nice (emollient), moisturizes, helps to reduce tackiness, and also has some foam boosting properties. It is often used in light, watery formulas to give them an extra silky feel

A very classic, old-school cleansing agent, a soap (the sodium salt of Stearic Acid). It is known for its rich, creamy foam and being quite harsh on the skin

If it's not in a soap bar, it can also function as an emulsifier or consistency agent. 

What-it-does: moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0

It's a sweet tasting sugar substitute that helps your skin to hold onto water when used in cosmetic products. It also helps to thicken up products and give them a bit more slip. 

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

What-it-does: emulsifying, surfactant/cleansing, viscosity controlling | Irritancy: 0 | Comedogenicity: 2

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. 

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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.

It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol

The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.

Honey - goodie
Also-called: Mel | What-it-does: soothing, moisturizer/humectant, antimicrobial/antibacterial

We all know honey as the sweet, gooey stuff that is lovely to sweeten a good cup of tea and we have good news about putting honey all over our skin. It is just as lovely on the skin as it is in the tea. 

The great review article about honey in the Journal of Cosmetic Dermatology writes that it is arguably the oldest skincare ingredient and evidence from around 4500 BC mentions honey in some eye cream recipes. Chemically speaking, it is a bee-derived, supersaturated sugar solution.  About 95% of honey dry weight is sugar and the other 5% consists of a great number of other minor components including proteins, amino acids, vitamins, enzymes, and minerals

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This unique and complex chemical composition gives honey a bunch of nice skin care properties: it is very moisturizing, has soothing and antioxidant abilities as well as significant antibacterial and antifungal magic powers. There is also a lot of empirical evidence with emerging scientific backup that honey dressing promotes the healing of wounds and burns.

One tricky thing about honey though, is that it can have lots of different floral sources and different types of honey have a somewhat different composition and thus somewhat different properties. For example, the darker the honey the richer it is in antioxidant phenolic compounds.  Two special types of honey are acacia and manuka. The former is unique and popular because of its higher than usual fructose content that makes it more water-soluble and easier to stabilize in cosmetic formulas. The latter comes from the Leptospermum Scoparium tree native to New Zeland and its special thing is its extra strong antibacterial power due to a unique component called methylglyoxal.  

Overall, honey is a real skin-goodie in pretty much every shape and form, and it is a nice one to spot on the ingredient list. 

Caffeine - goodie
What-it-does: antioxidant

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. 

We don't have description for this ingredient yet.

What-it-does: chelating, buffering

A little helper ingredient that is used to adjust the pH of the product. It also helps to keep products stay nice longer by neutralizing the metal ions in the formula (they usually come from water). 

We don't have description for this ingredient yet.

Also-called: Hibiscus Extract;Hibiscus Sabdariffa Flower Extract

We don't have description for this ingredient yet.

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 moisturizer/humectant | solvent
irritancy, com. 0, 1
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 emollient | moisturizer/humectant
A type of silicone that makes the skin smooth and nice (emollient), moisturizes and helps to reduce the tackiness of the products. [more]
what‑it‑does surfactant/cleansing | emulsifying | viscosity controlling
A very classic, old-school cleansing agent, a soap (the sodium salt of Stearic Acid). It is known for its rich, creamy foam and being quite harsh on the skin. If it's not in a soap bar, it can also function as an emulsifier or consistency agent.  [more]
what‑it‑does moisturizer/humectant
irritancy, com. 0, 0
It's a sweet tasting sugar substitute that helps your skin to hold onto water when used in cosmetic products. It also helps to thicken up products and give them a bit more slip.  [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 moisturizer/humectant | solvent
irritancy, com. 0, 0
A common glycol that improves the freeze-thaw stability of products. It's also a solvent, humectant and to some extent a penetration enhancer. [more]
what‑it‑does emulsifying | surfactant/cleansing | viscosity controlling
irritancy, com. 0, 2
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 moisturizer/humectant | emollient
A handy multi-tasking ingredient that gives the skin a nice, soft feel and also boosts the effectiveness of other preservatives. [more]
what‑it‑does soothing | moisturizer/humectant | antimicrobial/antibacterial
The sweet, gooey, sugar-laden stuff with skin moisturizing, soothing, antibacterial and some antioxidant properties. [more]
what‑it‑does antioxidant
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 chelating | buffering
A helper ingredient that is used to adjust the pH of the product. Also helps to keep products stay nice longer by neutralizing the metal ions in the formula. 
what‑it‑does viscosity controlling | viscosity controlling