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Zelens Stem Complex

Stem Complex

Zelens’ deeply replenishing Stem Complex Rejuvenating Overnight Treatment will transform the tone, texture and vitality of your complexion while you’re sleeping, thanks to a unique, anti-ageing complex enriched with powerful [more] [more] peptides and the latest discoveries in stem cell research. The innovative ‘Stem Complex’ does not contain vegetable stem cells but instead, contains high-tech ingredients that take advantage of their self-renewing nature – protecting and maintaining the ‘niche’ environment of epidermal skin cells to encourage optimal regenerative function. [less]
Uploaded by: rali on

Skim through

Ingredient name what-it-does irr., com. ID-Rating
Water (Aqua) solvent
Glycerin skin-identical ingredient, moisturizer/​humectant, perfuming, solvent, viscosity controlling 0, 0 superstar
Ethylhexyldodecanol
Phytosteryl Canola Glycerides
Hydrogenated Polydecene emollient, perfuming, solvent
Propylene Glycol moisturizer/​humectant, solvent, viscosity controlling 0, 0
Methylsilanol Hydroxyproline Aspartate
Cyclopentasiloxane emollient, solvent
Pentaerythrityl Tetraethylhexanoate emollient, viscosity controlling
Polysilicone-11
Butylene Glycol moisturizer/​humectant, solvent, viscosity controlling 0, 1
Polyacrylamide viscosity controlling
Dimethicone emollient 0, 1
Phenoxyethanol preservative
C13-14 Isoparaffin emollient, viscosity controlling, solvent
Acrylates/Carbamate Copolymer
Triethanolamine buffering 0, 2
Carbomer viscosity controlling 0, 1
Ozonized Oryza Sativa Callus Culture Extract
Sodium Hyaluronate skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Laureth-7 emulsifying, surfactant/​cleansing
Fragrance (Parfum) perfuming icky
Disodium EDTA chelating, viscosity controlling
Ethylhexylglycerin preservative
Xanthan Gum viscosity controlling, emulsifying, surfactant/​cleansing
Dextran viscosity controlling
Salicylic Acid exfoliant, anti-acne, soothing, preservative superstar
Potassium Sorbate preservative
Sodium Benzoate preservative
Acetyl Tetrapeptide-2 cell-communicating ingredient goodie
Linalool perfuming icky
Helichrysum Italicum Extract soothing
Trifluoroacetyl Tripeptide-2 cell-communicating ingredient goodie
Pentapeptide-31

Zelens Stem Complex
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. 

Glycerin - superstar
Also-called: Glycerol | What-it-does: skin-identical ingredient, moisturizer/humectant, perfuming, solvent, viscosity controlling | 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 >>

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Also-called: Alphaflow | What-it-does: emollient, perfuming, solvent

A hydrocarbon-based emollient that can come in different viscosities from silky-light through satiny-smooth to luxurious, rich. It forms a non-occlusive film on the surface of the skin and brings gloss without greasiness to the formula. It's a very pure and hypoallergenic emollient that's also ideal for baby care products. 

What-it-does: moisturizer/humectant, solvent, viscosity controlling | 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 >>

We don't have description for this ingredient yet.

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.

A high-molecular-weight emollient ester that makes your skin nice and smooth. It leaves a non-oily, light, "wet" feel on the skin. 

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

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

What-it-does: 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. 

What-it-does: viscosity controlling

It's a film-forming and thickening polymer (a large molecule composed of many repeated subunits) that comes to the formula usually as part of an emulsifier, thickener trio (with C13-14 Isoparaffin and Laureth-7, trade named Sepigel 305). This trio is an easy-to-use liquid that helps to create nice, non-tacky gel formulas

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). 

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 petroleum derived emollient and thickener. It often comes to the formula as part of an emulsifier, thickener trio (with Polyacrylamide and Laureth-7). This trio is an easy-to-use liquid that helps to create nice, non-tacky gel formulas. 

We don't have description for this ingredient yet.

What-it-does: buffering | Irritancy: 0 | Comedogenicity: 2

It’s a little helper ingredient that helps to set the pH of a cosmetic formulation to be just right. It’s very alkaline (you know the opposite of being very acidic): a 1% solution has a pH of around 10.

It does not have the very best safety reputation but in general, you do not have to worry about it. 

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What is true is that if a product contains so-called N-nitrogenating agents (e.g.: preservatives like 2-Bromo-2-Nitropropane-1,3-Diol, 5-Bromo-5-Nitro- 1,3-Dioxane or sodium nitrate - so look out for things with nitro, nitra in the name) that together with TEA can form some not nice carcinogenic stuff (that is called nitrosamines). But with proper formulation that does not happen, TEA in itself is not a bad guy. 

But let’s assume a bad combination of ingredients were used and the nitrosamines formed. :( Even in that case you are probably fine because as far as we know it cannot penetrate the skin. 

But to be on the safe side, if you see Triethanolamine in an INCI and also something with nitra, nitro in the name of it just skip the product, that cannot hurt.

What-it-does: viscosity controlling, emulsion stabilising | Irritancy: 0 | Comedogenicity: 1

A big molecule created from repeated subunits (a polymer of acrylic acid) that magically converts a liquid into a nice gel formula.  It usually has to be neutralized with a base (such as sodium hydroxide) for the thickening to occur and it creates viscous, clear gels that also feel nice and non-tacky on the skin. No wonder, it is a very popular and common ingredient.

We don't have description for this ingredient yet.

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).

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.

Also-called: Fragrance, Parfum;Parfum/Fragrance | 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 than fragrance is not your best friend - 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!). 

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: 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

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). 

What-it-does: viscosity controlling

We don't have description for this ingredient yet.

Salicylic Acid - superstar
Also-called: BHA | What-it-does: exfoliant, anti-acne, soothing, preservative
  • It's one of the gold standard ingredients for treating problem skin
  • It can exfoliate skin both on the surface and in the pores
  • It's a potent anti-inflammatory agent
  • It's more effective for treating blackheads than acne
  • For acne combine it with antibacterial agents like benzoyl peroxide or azelaic acid
Read all the geeky details about Salicylic Acid here >>

What-it-does: preservative

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

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

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BTW, it’s also a food preservative and even has an E number, E202.

What-it-does: preservative

A helper ingredient that helps to make the products stay nice longer, aka preservative. It works mainly against fungi. 

It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.

Also-called: Thymulen 4 | What-it-does: cell-communicating ingredient

A four amino acid peptide that is claimed to mimic the youth hormone called thymopoietin. It works by compensating the loss of thymic factors that come with age and is thought to stimulate the skin immune defenses and to help the skin regenerate

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. 

What-it-does: soothing

We don't have description for this ingredient yet.

Also-called: Progeline | What-it-does: cell-communicating ingredient

A 3 amino-acid peptide that works by inhibiting the production of progerin, a cell-aging accelerator protein.  The manufacturer claims that Trifluoroacetyl Tripeptide-2 can bring back cell activity to a 20-year-old young cell level and the ingredient can nicely increase skin elasticity, firmness and reduce skin-sagging

In their in-vivo (made on real people) tests, they found that 2%  Progeline cream can lift the sagging jaw-line by up to 10% in 56 days and improve skin elasticity and firmness by about 20% in 28 days.

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 skin-identical ingredient | moisturizer/humectant | perfuming | solvent | viscosity controlling
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 | perfuming | solvent
A hydrocarbon-based emollient that can come in different viscosities from silky-light to luxurious, rich. It forms a non-occlusive film on the surface of the skin. [more]
what‑it‑does moisturizer/humectant | solvent | viscosity controlling
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 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 emollient | viscosity controlling
A high-molecular-weight emollient ester that makes your skin nice and smooth. It leaves a non-oily, light, "wet" feel on the skin. 
A type of silicone elastomer (rubber-like material with both viscosity and elasticity) whose major function is forming a nice film on the skin. [more]
what‑it‑does 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 viscosity controlling
A film-forming and thickening polymer (a large molecule composed of many repeated subunits) that comes to the formula usually as part of an emulsifier, thickener trio. [more]
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 preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]
what‑it‑does emollient | viscosity controlling | solvent
A petroleum-derived emollient and thickener. It often comes to the formula as part of an emulsifier, thickener trio. [more]
what‑it‑does buffering
irritancy, com. 0, 2
Helps to set the pH of a cosmetic formulation to be right. It’s very alkaline. [more]
what‑it‑does viscosity controlling
irritancy, com. 0, 1
A handy white powder that magically converts a liquid into a nice gel formula. [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 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 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 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 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 viscosity controlling | emulsifying | surfactant/cleansing
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does viscosity controlling
what‑it‑does exfoliant | anti-acne | soothing | preservative
One of the gold standard ingredients for treating problem skin. It can exfoliate skin both on the surface and in the pores (pH 3-4 needed) and it's a potent anti-inflammatory agent. [more]
what‑it‑does preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]
what‑it‑does cell-communicating ingredient
A four amino acid peptide that is claimed to mimic the youth hormone called thymopoietin. It works by compensating the loss of thymic factors that come with age and is thought to stimulate the skin immune defenses and to help the skin regenerate. 
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 soothing
what‑it‑does cell-communicating ingredient
A 3 amino-acid peptide that works by inhibiting the production of progerin, a cell-aging accelerator protein.  The manufacturer claims that Trifluoroacetyl Tripeptide-2 can bring back cell activity to a 20-year-old young cell level and the ingredient can nicely increase skin elasticity, firmness and reduce skin-sagging. [more]