Follow us on our new Insta page »
Zelens Intense Defence Antioxidant Serum

Zelens
Intense Defence Antioxidant Serum

A potent antioxidant serum formulated with a unique blend of synergistic ingredients to help fight against three types of free radicals (ROS, RNS, RCS) and defend from environmental assaults. This [more] [more] lightweight, hydrating formulation supports natural collagen production and combats the effects of glycation to reduce the appearance of fine lines and wrinkles. [less]
Uploaded by: gladysdaniel_ on 09/04/2017

Skim through

Ingredient name what-it-does irr., com. ID-Rating
Aqua (Water) solvent
Glycerin skin-identical ingredient, moisturizer/​humectant 0, 0 superstar
C12-15 Alkyl Benzoate emollient, antimicrobial/​antibacterial
Squalane skin-identical ingredient, emollient 0, 1 goodie
Cyclopentasiloxane emollient, solvent
Sodium Hyaluronate skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Superoxide Dismutase antioxidant goodie
Thioctic Acid antioxidant goodie
Ubiquinone antioxidant goodie
Ascorbyl Tetraisopalmitate antioxidant, skin brightening goodie
Bisabolol soothing goodie
Perilla Frutescens Leaf Extract
Camellia Sinensis Leaf Extract antioxidant, soothing, antimicrobial/​antibacterial superstar
Centella Asiatica Extract soothing, antioxidant, moisturizer/​humectant goodie
Ginkgo Biloba Leaf Extract
Pinus Strobus Bark Extract
Echinacea Angustifolia Leaf Extract moisturizer/​humectant, soothing
Tocopheryl Acetate antioxidant 0, 0
Hydrolyzed Soy Protein moisturizer/​humectant
Hydrolyzed Wheat Protein moisturizer/​humectant goodie
Dimethylmethoxy Chromanol antioxidant goodie
Hydrolyzed Sesame Protein Pg-Propyl Methylsilanediol
Tripeptide-1 cell-communicating ingredient goodie
Lactic Acid exfoliant, moisturizer/​humectant superstar
Polyacrylamide viscosity controlling
Phenoxyethanol preservative
Dimethicone emollient 0, 1
Acrylates Copolymer viscosity controlling
C13-14 Isoparaffin emollient, viscosity controlling
Dimethicone Crosspolymer viscosity controlling
Laureth-7 emulsifying, surfactant/​cleansing
Ethylhexylglycerin preservative
Polysilicone-11
Vp/Polycarbamyl Polyglycol Ester
Butylene Glycol moisturizer/​humectant, solvent 0, 1
Caprylyl Glycol moisturizer/​humectant, emollient
Xanthan Gum viscosity controlling
Parfum (Fragrance) perfuming icky
Linalool perfuming icky

Zelens Intense Defence Antioxidant 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. 

Expand to read more

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 >>

An often used emollient with a light and silky feel. It's very mild to both skin and eyes and spreads nicely and easily. It's often used in sunscreens as it's also an excellent solvent for sunscreen agents. 

Squalane - goodie
What-it-does: skin-identical ingredient, emollient | Irritancy: 0 | Comedogenicity: 1

It seems to us that squalane is in fashion and there is a reason for it. Chemically speaking, it is a saturated  (no double bonds) hydrocarbon (a molecule consisting only of carbon and hydrogen), meaning that it's a nice and stable oily liquid with a long shelf life. 

It occurs naturally in certain fish and plant oils (e.g. olive), and in the sebum (the oily stuff our skin produces) of the human skin. As f.c. puts it in his awesome blog post, squalane's main things are "emolliency, surface occlusion, and TEWL prevention all with extreme cosmetic elegance". In other words, it's a superb moisturizer that makes your skin nice and smooth, without being heavy or greasy.

Expand to read more

Another advantage of squalane is that it is pretty much compatible with all skin types and skin conditions. It is excellent for acne-prone skin and safe to use even if you have fungi-related skin issues, like seborrhea or fungal acne.

The unsaturated (with double bonds) and hence less stable version of Squalane is Squalene, you can read about it here >> 

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: 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". 

Expand to read more

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: SOD | What-it-does: antioxidant

Superoxide Dismutase - or in short SOD - is the body's smart antioxidant enzyme that protects the cells from highly reactive, cell-damaging superoxide radicals (O2−).

You have probably read the terms "free radicals" and "antioxidants" a thousand times, and you know that free radicals are the evil guys, and antioxidants are the good guys. So superoxide radical is a very common free radical that can cause all kinds of cell damages and superoxide dismutase is an enzyme that catalyzes the conversion of superoxide radicals into molecular oxygen and hydrogen peroxide (btw, this one has to be further converted by other antioxidant enzymes, called catalases).

Expand to read more

The extra nice thing about SOD is that it remains intact during the neutralization process and can continue its magic, while non-enzymatic antioxidants (like vitamin E) are used up during neutralization.

The efficacy studies of topical SOD are promising. In-vitro (made in the lab) tests show that SOD is a more effective antioxidant than vitamin E, green tea extract, and MAP. There is also an in-vivo (made on real people) study that measured how SOD can reduce the redness caused by UV rays and it was much more effective than vitamin E (pure or acetate form) and ascorbyl palmitate

All in all, SOD is a really potent antioxidant and slathering it all over yourself is a great way to give the skin a little extra help in protecting itself from all the bad environmental things out there. 

Thioctic Acid - goodie
Also-called: Alpha-Lipoic Acid | What-it-does: antioxidant

Alpha-Lipoic Acid (ALA) is a great antioxidant that's also part of the body's natural antioxidant system. It's soluble both in water-rich and lipid-rich environments so it's versatile and can interact with many types of evil oxidants as well as other nice antioxidants. 

ALA seems to be a great choice for topical use as studies show it can penetrate the skin rapidly where it's converted to DHLA (dihydrolipoic acid), an even more potent antioxidant molecule.  A nicely designed (we mean double-blind, placebo-controlled) 12-week study from 2003 confirmed that 5% ALA cream can decrease skin roughness and improve general signs of photoaging statistically significantly.  A slight catch, though, is that burning and warmth in the skin was quite a common side effect, especially in the first 4 weeks. 

Expand to read more

All in all, ALA is definitely a research-proven, great antioxidant but if your skin is sensitive higher concentrations might not be for you.

Ubiquinone - goodie
Also-called: Coenzyme Q10 | What-it-does: antioxidant

Thanks to Nivea, Q10 is a pretty well-known ingredient and the fame and Beiersdorf's (the parent company of Nivea) obsession with it are not for no reason. It's an antioxidant found naturally in human cells where it plays a big role in energy production.

In fact, it's so important for energy production that if taken as an oral supplement it has a caffeine-like effect and if taken at night you will probably not sleep very well (so you should take it in the morning). Q10 supplementation is not a bad idea: it not only gives you energy but research also shows that oral Q10 increases the Q10 level of the skin (of course, it decreases with age like pretty much every good thing in the skin) and may help to reduce wrinkles. If you are not for supplements, dietary sources include fish, spinach, and nuts.

Expand to read more

As for skincare, Q10 comes in the form of a yellow, oil-soluble powder that's shown to absorb into the upper layer of the skin and act there like an awesome antioxidant. It not only has preventative effects but might also be able to reduce the depth of wrinkles, though 0.3% Q10 was used in the study that counts as really high (products containing that much should be very yellow!). 

Also-called: Form of Vitamin C, Ascorbyl Isotetrapalmitate, Ascorbyl Tetraisopalmitate, ATIP;Tetrahexyldecyl Ascorbate | What-it-does: antioxidant, skin brightening

Tetrahexyldecyl Ascorbate is a stable, oil-soluble form of skincare big shot Vitamin C. If you do not know, why Vitamin C is such a big deal in skincare, click here and read all about it. We are massive vitamin C fans and have written about it in excruciating detail.

So now, you know that Vitamin C is great and all, but it's really unstable and gives cosmetics companies many headaches. To solve this problem they came up with vitamin C derivatives, and one of them is Tetrahexyldecyl Ascorbate (let's call it ATIP in short).

Expand to read more

It's a really promising candidate (see below), but while reading all the goodness about it in a minute, do not forget that derivatives not only have to be absorbed into the skin but also have to be converted to pure vitamin C (ascorbic acid or AA) and the efficacy of the conversion is often unknown. In addition, vitamin C's three magic properties (antioxidant, collagen booster, skin brightener) are all properly proven in-vivo (on real people), but for the derivatives, it's mostly in-vitro studies or in the case of ATIP, it's in-vitro and done by an ingredient supplier.

With this context in mind let's see what ATIP might be able to do. First, it is stable (if pH < 5), easy to formulate and a joy to work with for a cosmetic chemist.

Second, because it's oil-soluble, its skin penetration abilities seem to be great. So great in fact, that it surpasses the penetration of pure vitamin C threefold at the same concentration and it penetrates successfully into the deeper layers of the skin (that is usually important to do some anti-aging work). There is also in-vitro data showing that it converts to AA in the skin. 

Third, ATIP seems to have all three magic abilities of pure vitamin C: it gives antioxidant protection from both UVB and UVA rays, it increases collagen synthesis (even more than AA) and it has a skin brightening effect by reducing melanogenesis by more than 80% in human melanoma cell cultures.

So this all sounds really great, but these are only in-vitro results at this point. We could find Tetrahexyldecyl Ascorbate mentioned only in one published in-vivo study that examined the anti-aging properties of a silicone formula containing 10% AA and 7% ATIP. The authors theorized that the 10% AA is released slowly from the silicon delivery system and probably stays in the upper layer of the skin to give antioxidant benefits, while ATIP penetrates more rapidly and deeply and gives some wrinkle-reducing benefits. The study was a small (10 patients), double-blind experiment, and the formula did show some measurable anti-aging results. However, it is hard to know how much pure vitamin C or ATIP can be thanked.

Bottom line: a really promising, but not well-proven vitamin C derivative that can be worth a try especially if you like experimenting (but if you like the tried and true, pure vitamin C will be your best bet).

Bisabolol - goodie
Also-called: Alpha-Bisabolol | What-it-does: soothing

It's one of the active parts of Chamomile that contains about 30% of bisabolol. It's a clear oily fluid that is used in skincare as a nice anti-inflammatory and soothing ingredient. 

We don't have description for this ingredient yet.

Also-called: Green Tea | What-it-does: antioxidant, soothing, antimicrobial/antibacterial
  • Green tea is one of the most researched natural ingredients
  • The active parts are called polyphenols, or more precisely catechins (EGCG being the most abundant and most active catechin)
  • There can be huge quality differences between green tea extracts. The good ones contain 50-90% catechins (and often make the product brown and give it a distinctive smell)
  • Green tea is proven to be a great antioxidant, UV protectant, anti-inflammatory, anticarcinogenic and antimicrobial
  • Because of these awesome properties green tea is a great choice for anti-aging and also for skin diseases including rosacea, acne and atopic dermatitis
Read all the geeky details about Camellia Sinensis Leaf Extract here >>

Also-called: Gotu Kola, Tiger Grass | What-it-does: soothing, antioxidant, moisturizer/humectant

Centella Asiatica - or gotu kola as normal people call it  - has been used in folk medicine for hundreds of years. It’s traditionally used to improve small wounds, burns and scratches and it’s also a well known anti-inflammatory agent for eczema.

Recently science has taken an interest in Gotu Kola as well and it turns out it really has many active compounds with several benefits. Just for hard-core geeks, the main biologically active compounds are pentacyclic triterpenoid saponins called asiaticoside, madecassoside, asiatic and madecassic acid (also called centellosides).

Expand to read more

One of the biological activities of the centellosides is to be able to stimulate GAGs  (glycosaminoglycans - polysaccharides that are part of the liquidy stuff between our skin cells), and especially hyaluronic acid synthesis in our skin. This is probably one of the reasons why Centella Asiatica Extract has nice skin moisturizing properties that was confirmed by a 25 people, four weeks study along with Centella's anti-inflammatory effects.

Madecassoside can also help in burn wound healing through increasing antioxidant activity and enhancing collagen synthesis. Asiaticoside was shown to increase antioxidant levels on rats skin when applied at 0.2%. 

Centella Asiatica also often shows up in products that try to treat cellulite or striae. Of course, it cannot make a miracle but it might have some effect via regulating microcirculation and normalizing the metabolism in the cells of connective tissues. 

Bottom line: Gotu Kola is a great plant ingredient with proven wound healing, anti-inflammatory, and antioxidant properties. Nice to spot on any ingredient list.  

Also-called: Ginkgo Biloba Extract

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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. 

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant

A chemically chopped up version of wheat protein that consists mainly of amino acids (the building blocks), peptides (a couple of amino acids together), and proteins (lots of amino acids together). 

It has moisturizing and film-forming properties and  might be able to counteract the irritating effects of cleansing agents in cleansers and shampoos. It can also condition and repair damaged hair leaving it soft, silky and smooth.

Also-called: Lipochroman-6, LC-6 | What-it-does: antioxidant

A synthetic molecule that has a similar structure to α-Tocopherol (vitamin E) and works as a super potent antioxidant. It's known for not only protecting against reactive oxygen species (ROS) but also against reactive nitrogen species (RNS) (both are evil reactive molecules that cause damage to cells and tissues and are responsible for several mechanisms which trigger skin aging). 

There are different methods to evaluate the antioxidant power of an ingredient and according to the so-called TBA-assay, Dimethylmethoxy Chromanol is a more potent antioxidant than BHT, trolox or tocopherol. Its recommended dosage is only 0.01-0.05%, that also signals how potent Lipochroman-6 is. 

We don't have description for this ingredient yet.

Tripeptide-1 - goodie
Also-called: GHK, Kollaren | What-it-does: cell-communicating ingredient

A small, three amino acid (glycine-histidine-lysine or GHK) peptide that is famous for being a type I collagen fragment. The theory behind collagen-fragment peptides is that 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. So Tripeptide-1 is believed to be able to stimulate collagen production in the skin, and more collagen means fewer wrinkles and younger looking skin. FYI; Tripeptide-1 is the same peptide that can be found in the famous Matrixyl 3000, but in Matrixyl a palmitic acid is attached to it to increase its oil solubility and thus skin penetration.

Expand to read more

Another reason why Tripeptide-1 is especially famous is that it is not only a signal peptide but also a so-called carrier peptide that helps to stabilize and deliver copper in the skin. It has a high affinity for copper ions and likes to form a complex with them called Copper-Tripeptide-1 or GHK-Cu. GHK-Cu is a famous and well-researched peptide that does a bunch of things in the skin and we have a shiny explanation about it here

As for Tripeptide-1 in and of itself, without a palmitic acid or copper attached to it, it goes by the trade name Kollaren and according to the manufacturer, it not only stimulates collagen but also other essential skin proteins such as fibronectin, elastin, and laminin. Kollaren is also claimed to be beneficial for acne-prone skin as it can boost tissue repair and thus help acne scars to heal faster. 

Lactic Acid - superstar
  • It’s the second most researched AHA after glycolic acid
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It also has amazing skin hydrating properties
  • In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
Read all the geeky details about Lactic Acid here >>

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: 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. 

Expand to read more

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: 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. 

Expand to read more

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: viscosity controlling

A big polymer molecule that has a bunch of different versions and thus different uses. It can act as a film former,  as thickening agent, or it can increase the water-resistance in sunscreens. It is also used to entrap pigments/inorganic sunscreens within a micron size matrix for even coverage and easy application.

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. 

A high-molecular-weight silicone elastomer (rubber-like elastic material) that is usually blended with a base silicone fluid (such as dimethicone or cyclopentasiloxane) to give the formula a silky smooth feel and to act as a thickening agent.

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.

What-it-does: preservative

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

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.

We don't have description for this ingredient yet.

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.

Expand to read more

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. 

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.

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;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.  

Expand to read more

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!). 

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.

Expand to read more

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

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 emollient | antimicrobial/antibacterial
An often used emollient with a light and silky feel. It's very mild to both skin and eyes and spreads nicely and easily. It's often used in sunscreens as it's also an excellent solvent for sunscreen agents. 
what‑it‑does skin-identical ingredient | emollient
irritancy, com. 0, 1
An emollient and natural moisturizer that can be found also in the sebum (oily stuff our skin produces). It leaves a nice non-greasy, non-heavy feeling on the skin. [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 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
Superoxide Dismutase - or in short SOD - is the body's smart antioxidant enzyme that protects the cells from highly reactive, cell-damaging superoxide radicals (O2−). You have probably read the terms "free radicals" [more]
what‑it‑does antioxidant
Alpha-Lipoic Acid (ALA) is a great antioxidant that's also part of the body's natural antioxidant system. It's soluble both in water-rich and lipid-rich environments so it's versatile and can interact with many types of evil oxidants as well as other nice antioxidants. ALA seems to be a great choice for topical use as studies show it can penetrate the skin rapidl [more]
what‑it‑does antioxidant
Q10 - an antioxidant found naturally in human cells where it plays an important role in energy production. As for skincare, it works as an awesome antioxidant that might also be able to reduce wrinkle depth. [more]
what‑it‑does antioxidant | skin brightening
A stable, oil-soluble form of Vitamin C, that might have (in-vitro results) all the magic abilities of pure vitamin C (antioxidant, collagen booster, skin brightener). [more]
what‑it‑does soothing
One of the active parts of Chamomile that is used in skincare as a nice anti-inflammatory and soothing ingredient. [more]
what‑it‑does antioxidant | soothing | antimicrobial/antibacterial
Green Tea - one of the most researched natural ingredients that contains the superstar actives called catechins. It has proven antioxidant, anti-inflammatory, antimicrobial and anticarcinogenic properties. [more]
what‑it‑does soothing | antioxidant | moisturizer/humectant
Centella Asiatica - or gotu kola as normal people call it  - has been used in folk medicine for hundreds of years. It’s traditionally used to improve small wounds, burns and scratches and it’s also a well known anti-inflammatory agent for eczema.Recently science has taken an interest in Gotu Kola as well and it turns out it really has many active compounds with several benefits. [more]
what‑it‑does moisturizer/humectant | soothing
what‑it‑does antioxidant
irritancy, com. 0, 0
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 moisturizer/humectant
what‑it‑does moisturizer/humectant
A chemically chopped up version of wheat protein with moisturizing and film-forming properties. [more]
what‑it‑does antioxidant
A synthetic molecule that works as a super potent antioxidant. It's known for not only protecting against reactive oxygen species (ROS) but also against reactive nitrogen species (RNS).  [more]
what‑it‑does cell-communicating ingredient
A small, three amino acid (glycine-histidine-lysine or GHK) peptide that is famous for being a type I collagen fragment. The theory behind collagen-fragment peptides is that 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. [more]
what‑it‑does exfoliant | moisturizer/humectant
A superstar AHA that not only exfoliates skin but is also a very good moisturizer. In higher concentration (10% and up) it can even improve skin firmness, thickness, and wrinkles. [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 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
irritancy, com. 0, 1
A very common silicone that gives both skin and hair a silky smooth feel. It also forms a protective barrier on the skin and fills in fine lines. Also used for scar treatment. [more]
what‑it‑does viscosity controlling
A big polymer molecule that has a bunch of different versions and thus different uses. It can act as a film former,  as a thickening agent, or it can increase the water-resistance in sunscreens. [more]
what‑it‑does emollient | viscosity controlling
A petroleum-derived emollient and thickener. It often comes to the formula as part of an emulsifier, thickener trio. [more]
what‑it‑does viscosity controlling
A high-molecular-weight silicone elastomer (rubber-like elastic material) that is usually blended with a base silicone fluid (such as dimethicone or cyclopentasiloxane) to give the formula a silky smooth feel and to act as a thickening agent. [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 preservative
It can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too. [more]
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
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 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 viscosity controlling
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 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]