Follow us on our new Insta page »
Skin Functional Caffeine & Peptide Serum

Caffeine & Peptide Serum

An intensive eye serum that expertly targets dark circles and puffiness while addressing fine laugh lines around the eye area.
Uploaded by: diana.cucu on

Skin Functional Caffeine & Peptide Serum
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. 

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. 

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 >>

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. 

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.

We don't have description for this ingredient yet.

Also-called: EYESERYL | What-it-does: cell-communicating ingredient, moisturizer/humectant

A four amino acid peptide that is claimed to improve puffy eye bags via its anti-oedema and anti-glycation effects.

To back this claim up, the manufacturer created an in-vivo study with 20 volunteers using 10% of EYESERYL (that comes down to 0.01% (!) of the pure peptide) and found that by day 15, 70% of the volunteers improved, while 95% of the volunteers improved by the end of the study (60 days). About third of them improved only slightly, third of them showed an ok improvement and third showed a good improvement. They also have pretty convincing before and after photos, so we can tell you that for the lucky ones, the improvement can be real and visible.

But, the thing is that puffiness around the eyes can have multiple reasons and one of the major ones is fat accumulation that might happen as we age. No miracle cream or ingredient can do much about that, however, another common reason is water accumulation. If the reason behind your eye bags is this latter one, trying an eye cream with Acetyl Tetrapeptide-5 can be a good idea and might bring nice improvements. 

Dipeptide-2 - goodie
Also-called: Part of Eyeliss | What-it-does: cell-communicating ingredient

A tiny peptide with only two amino acids (amino acids are the building block of proteins, and peptides are a few amino acids attached together), Valine and Tryptophan. It's part of a 3 actives complex called Eyeliss (with HMC and Palmitoyl Tetrapeptide-7) that's supposed to fight under-eye bags

The manufacturer claims that this dipeptide in Eyeliss can increase lymphatic circulation and the three actives together represent a "global approach to treating puffy eyes". The clinical study of the manufacturer with 20 people and 3% Eyeliss showed improvement after 56 days for 70% of the participants.

Also-called: Argireline, Acetyl Hexapeptide-3 | What-it-does: cell-communicating ingredient, moisturizer/humectant

If you see a cosmetic product that claims that it has "Botox-like effect" then two things are almost certain: one, the product overpromises and two, it contains Argireline. 

So this one is the famous peptide that's marketed by its manufacturer as the "Botox in a jar". The basis for this claim is that it targets the same wrinkle forming mechanism (wrinkles caused by facial muscle movement) as Botox, but the way it works is very different. In addition, the extent to which it can prevent muscles from contracting (and to smooth wrinkles) is very different (otherwise why would anyone use still Botox?). 

The manufacturer did several studies to prove that Argireline really works and it does (just not as well as Botox). In-vivo (made on real people) tests showed that using 10% Argireline solution around the eyes for 15 days decreased wrinkles depth by 17%. A Spanish University also did some research and found that Argireline increased the level of skin moisturization and decreased both the depth and width of wrinkles "significantly". 

This means, Acetyl Hexapeptide-8 does have some ability to smooth wrinkles (but not as well as Botox - sorry, if we sound like a broken record). Also, we have to agree with TruthInAging, that it's not a collagen builder and not a preventer of structural aging (think vitamin C, AHAs or retinol); it's just a quick fix. If you are looking for one, this could be your thing. If you are more of a "let's treat this aging thing properly" type, then it's probably not your thing.

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.

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: Part of Matrixyl 3000, Pal-GHK, Formerly also Palmitoyl Oligopeptide | What-it-does: cell-communicating ingredient

A really famous peptide that is part of Matrixyl 3000, the most sold peptide complex in the word. Before we go and find out what the big deal with Matrixyl 3000 is, let's just focus on Palmitoyl Tripeptide-1 itself for a bit.

It's a small three amino acid (they are the building blocks of all proteins) peptide with the amino sequence of glycine-histidine-lysine, or GHK. GHK is attached to palmitic acid (a fatty acid) to increase oil solubility and skin penetration. 

The GHK part is the important one as it's a type I collagen fragment. When collagen naturally breaks down in the skin, the resulting peptide fragments signal to the skin that it should get to work and create some nice, new collagen. Adding in collagen fragment peptides, like GHK, might trick the skin into thinking that collagen has broken down and it's time to create some more.

Therefore, Palmitoyl Tripeptide-1 is believed to be able to stimulate collagen production in the skin, and more collagen means fewer wrinkles and younger looking skin. 

In Matrixyl 3000, Palmitoyl Tripeptide-1 is coupled with Palmitoyl Tetrapeptide-7  and the duo works in synergy to reduce wrinkles and give younger looking skin. According to the manufacturer's in-vivo (made on real people) test, applying 3% Matrixyl 3000 twice a day for 2 months resulted in all of the following things:

  • 39.4% reduction in surface occupied by deep wrinkles
  • 32.9% reduction in main wrinkle density
  • 19.9% reduction in main wrinkle average depth
  • 16% improvement in roughness
  • 16.2% in lifting effect
  • 5.5% improvement in elasticity
  • 15.5% improvement in skin tone

Manufacturer results, of course, always have to be taken with a pinch of salt, but if you like peptides, the Matryxil 3000 duo is one of the best-proven and most well-known ones and it's something that is worth trying.

Also-called: Part of Matrixyl 3000, Pal-GQPR, Previously Palmitoyl Tetrapeptide-3 | What-it-does: cell-communicating ingredient

A four amino acid peptide with the amino sequence of glycine-glutamine-proline-arginine. It is attached to palmitic acid (a fatty acid)  to increase oil solubility and skin penetration. 

It works by reducing the production of the signal moleculeinterleukin-6 (IL-6) which promotes inflammation in the skin and less inflammation means slower degradation of important things (like collagen) that results in younger looking skin for a longer time. 

It works in synergy with its pal, Palmitoyl Tripeptide-1 in the famous Matrixyl 3000 complex. You can read some more about the famous duo here.

What-it-does: emollient

A super common emollient that makes your skin feel nice and smooth. It comes from coconut oil and glycerin, it’s light-textured, clear, odorless and non-greasy. It’s a nice ingredient that just feels good on the skin, is super well tolerated by every skin type and easy to formulate with. No wonder it’s popular. 

What-it-does: emollient, emulsifying

It's the chemically chopped up version of normal lecithin. Most often it's used to create liposomes and to coat and stabilize other ingredients. 

Also-called: Matrixyl synthe'6 | What-it-does: cell-communicating ingredient

It's a pretty new peptide trade-named MATRIXYL™ synthe’6. The manufacturer claims that it can boost the production of 6 major components of the skin matrix (collagen I, III, IV, fibronectin, hyaluronic acid and laminin 5) that result in more even skin and fewer wrinkles particularly on the forehead and crow's feet. Using 2% of the active for two months daily, women reported a decrease in wrinkles by 31% up to 100%.

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. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Ectoin - goodie
Also-called: 28Extremoin

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

What-it-does: antioxidant

We don't have description for this ingredient yet.

Ascorbic Acid - superstar
Also-called: Vitamin C, L-ascorbic acid | What-it-does: antioxidant, skin brightening, buffering
  • Works best between a concentration of 5-20%
  • Boosts the skin’s own collagen production
  • Fades pigmentation and brown spots
  • If used under sunscreen it boosts its UV protection
  • Extremely unstable and oxidizes very easily in presence of light or air
  • Stable in solutions with water only if pH is less than 3.5 or in waterless formulations
  • Vit E + C work in synergy and provide superb photoprotection
  • Ferulic acid doubles the photoprotection effect of Vit C+E and helps to stabilize Vit C
  • Potent Vit. C serums might cause a slight tingling on sensitive skin
Read all the geeky details about Ascorbic Acid here >>

An amino acid sugar that can be found in the skin and does there good and important things. One of them is that it's a precursor for the biosynthesis of superstar moisturizer, hyaluronic acid. So acetyl glucosamine itself is also an important skin-identical ingredient and natural moisturizing factor.

But that is not all, acetyl glucosamine has two other great properties proved by double-blind clinical trials. First, it's a promising ingredient against wrinkles:  2% can improve wrinkles, particularly in the eye area.

Second, the same amount can also fade - always stubborn - brown spots. (Do not expect magic, though - the photos from the study show the difference after 8 weeks of daily use. The difference is visible, but not that big. It's always good to have realistic expectations. :))  Combined with skincare superstar niacinamide the duo is synergistic and is more effective at improving hyperpigmentation, so if you are after the skin-lightening benefit look out for products that contain both. 

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: 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

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: 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. 

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.

What-it-does: preservative

A pale yellow solid material that helps cosmetic products not to go wrong too soon aka preservative.

It has antioxidant and antibacterial activity and can be used synergistically with IT-preservative phenoxyethanol or 1,2-Hexanediol and Caprylyl Glycol to form a broad spectrum preservative system for cosmetic 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. 

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.

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 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 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 cell-communicating ingredient | moisturizer/humectant
A four amino acid peptide that is claimed to improve puffy eye bags via its anti-oedema and anti-glycation effects.To back this claim up, the manufacturer created an in-vivo study with 20 volunteers using 10% of EYESERYL (that comes down to 0.01% (!) of the pure peptide) and found that by day 15, 70% of the volunteers improved, while 95% of the volunteers improved by the end of the study (60 d [more]
what‑it‑does cell-communicating ingredient
A tiny peptide with only two amino acids (amino acids are the building block of proteins, and peptides are a few amino acids attached together), Valine and Tryptophan. [more]
what‑it‑does cell-communicating ingredient | moisturizer/humectant
Argireline - famous peptide that's often referred to as "Botox in a jar". In reality, it's nowhere near that powerful, but it can smooth wrinkles to some extent by preventing facial muscles from contracting. [more]
what‑it‑does moisturizer/humectant | solvent | viscosity controlling
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 cell-communicating ingredient
A three amino acid peptide that is part of famous peptide duo, Matrixyl 3000. It's a type I collagen fragment that might be able to trick the skin to think that collagen broke down and it's time to create some new one. [more]
what‑it‑does cell-communicating ingredient
The pal of Palmitoyl Tripeptide-1 in Matrixyl 3000. A four amino acid peptide that works by reducing the production of the signal molecule, inteleukin-6 (IL-6) that promotes inflammation in the skin. [more]
what‑it‑does emollient
A very common emollient that makes your skin feel nice and smooth. Comes from coconut oil and glycerin, it’s light-textured, clear, odorless and non-greasy. [more]
what‑it‑does emollient | emulsifying
It's the chemically chopped up version of normal lecithin. Most often it's used to create liposomes and to coat and stabilize some other ingredient. 
what‑it‑does cell-communicating ingredient
Matrixyl synthe'6 - A peptide that is claimed to be able to boost the production of 6 major components of the skin matrix (including collagen and hyaluronic acid). [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 antioxidant
what‑it‑does antioxidant | skin brightening | buffering
Pure Vitamin C. A skincare superstar that is clinically proven to boost collagen production (in 5-20% concentration), fade hyperpigmentation and boost UV protection under sunscreen. Also, it's extremely unstable and hard to formulate. [more]
what‑it‑does skin-identical ingredient | skin brightening
An amino sugar that helps the skin to stay hydrated, is also promising against wrinkles and can help to fade brown spots particularly when combined with niacinamide. [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 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 viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
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 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 preservative
A pale yellow solid material with antioxidant and antibacterial activity. Combined with other preservatives it helps to form a broad spectrum preservative system for cosmetic products.  [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]