Follow us on our new Insta page »
Dermaquest Advanced C Infusion Serum

Advanced C Infusion Serum

A creamy, multifunctional serum that brightens, tightens, and repairs better than ever before while protecting against UV and free-radical damage.
Uploaded by: dont_forget_me_2009 on

Highlights

Skim through

Ingredient name what-it-does irr., com. ID-Rating
Water (Aqua) solvent
Tetrahexyldecyl Ascorbate antioxidant, skin brightening goodie
Caprylic/Capric Triglyceride emollient
Glycerin skin-identical ingredient, moisturizer/​humectant 0, 0 superstar
Hexyl Laurate emollient
Sorbitol moisturizer/​humectant 0, 0
Butylene Glycol moisturizer/​humectant, solvent 0, 1
Stearic Acid emollient, viscosity controlling 0, 2-3
Glyceryl Stearate emollient, emulsifying 0, 1
PEG-100 Stearate surfactant/​cleansing, emulsifying 0, 0
Cetyl Alcohol emollient, viscosity controlling 2, 2
Sorbitan Monostearate emulsifying 1, 0
Polysorbate 60 emulsifying, surfactant/​cleansing
Dimethicone emollient 0, 1
PPG-12/Smdi Copolymer emollient
Squalane skin-identical ingredient, emollient 0, 1 goodie
Ethoxydiglycol solvent, moisturizer/​humectant, perfuming 0, 0
Sodium Hyaluronate skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Sodium Mannose Phosphate moisturizer/​humectant
Mannose moisturizer/​humectant goodie
Hydroxyapatite abrasive/​scrub
Acetyl Zingerone antioxidant, chelating
Mannitol moisturizer/​humectant goodie
Ergothioneine antioxidant
Hydrolyzed Glycosaminoglycans moisturizer/​humectant
Propylene Glycol moisturizer/​humectant, solvent 0, 0
Tocopheryl Acetate antioxidant 0, 0
Cetearyl Ethylhexanoate emollient
Di-PPG-2 Myreth-10 Adipate emollient, surfactant/​cleansing
Linoleic Acid skin-identical ingredient, emollient, surfactant/​cleansing goodie
Ferulic Acid antioxidant, antimicrobial/​antibacterial goodie
Glycine Soja (Soybean) Sterols emollient
Phospholipids skin-identical ingredient, emollient goodie
Citrus Aurantium Dulcis (Orange) Callus Culture Extract
Ectoin antioxidant, soothing, moisturizer/​humectant goodie
Cyclotetrapeptide-24 Aminocyclohexane Carboxylate antioxidant
Retinol cell-communicating ingredient superstar
Arabidopsis Thaliana Extract antioxidant
Micrococcus Lysate
Plankton Extract
Glucosamine Hcl
Sea Water moisturizer/​humectant, solvent
Pullulan
Hydrolyzed Rhodophyceae Extract
Chlorella Vulgaris Extract
Laminaria Digitata Extract
Saccharide Isomerate moisturizer/​humectant goodie
Saccharomyces Cerevisiae Extract moisturizer/​humectant goodie
Urea skin-identical ingredient, moisturizer/​humectant goodie
Polysorbate 20 emulsifying, surfactant/​cleansing 0, 0
Bakuchiol cell-communicating ingredient, antioxidant, antimicrobial/​antibacterial goodie
Isosorbide Dicaprylate cell-communicating ingredient, moisturizer/​humectant goodie
Alcohol antimicrobial/​antibacterial, solvent, viscosity controlling icky
Lecithin emollient, emulsifying goodie
Phenoxyethanol preservative
Caprylyl Glycol moisturizer/​humectant, emollient
Ethylhexylglycerin preservative
Hexylene Glycol solvent, emulsifying, perfuming, surfactant/​cleansing 0-1, 0-2
Sodium Benzoate preservative
Gluconolactone exfoliant, chelating superstar
Calcium Gluconate moisturizer/​humectant
Magnesium Aluminum Silicate viscosity controlling 0, 0
Xanthan Gum viscosity controlling
Disodium EDTA chelating
BHA antioxidant, preservative icky
BHT antioxidant, preservative
Citrus Aurantium Dulcis (Orange) Peel Oil perfuming icky
Limonene perfuming, solvent icky
Linalool perfuming icky
Citral perfuming icky
Geraniol perfuming icky

Dermaquest Advanced C Infusion Serum
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. 

Also-called: Form of Vitamin C, THDA | 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 THDA in short).

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. 

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 for dry skin at higher concentrations up to 20-40%
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

What-it-does: emollient

A fast spreading emollient ester (hexyl alcohol + lauric acid) that's used in water in oil emulsions or in water-free formulas. It gives a light skin feel. 

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. 

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.

What-it-does: emollient, viscosity controlling | Irritancy: 0 | Comedogenicity: 2-3

A common multi-tasker fatty acid. It makes your skin feel nice and smooth (emollient), gives body to cream type products and helps to stabilize water and oil mixes (aka emulsions).

What-it-does: emollient, emulsifying | Irritancy: 0 | Comedogenicity: 1

A super common, waxy, white, solid stuff that helps water and oil to mix together, gives body to creams and leaves the skin feeling soft and smooth.

Chemically speaking, it is the attachment of a glycerin molecule to the fatty acid called stearic acid. It can be produced from most vegetable oils (in oils three fatty acid molecules are attached to glycerin instead of just one like here) in a pretty simple, "green" process that is similar to soap making. It's readily biodegradable.

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

A very common water-loving surfactant and emulsifier that helps to keep water and oil mixed nicely together. 

It's often paired with glyceryl stearate - the two together form a super effective emulsifier duo that's salt and acid tolerant and works over a wide pH range. It also gives a "pleasing product aesthetics", so no wonder it's popular.

What-it-does: emollient, viscosity controlling, emulsion stabilising | Irritancy: 2 | Comedogenicity: 2

A so-called fatty (the good, non-drying kind of) alcohol that does all kinds of things in a skincare product: it makes your skin feel smooth and nice (emollient), helps to thicken up products and also helps water and oil to blend (emulsifier). Can be derived from coconut or palm kernel oil.

What-it-does: emulsifying | Irritancy: 1 | Comedogenicity: 0

A popular, vegetable-derived oil-loving emulsifier that helps water to mix with oil. In itself, it is suitable for water-in-oil emulsions (where water droplets are dispersed in oil), but it is more often used as a co-emulsifier next to other, water-loving emulsifiers. 

Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the fatty acid Stearic Acid, that creates a partly water (the sorbitan part) and partly oil soluble (stearic part) molecule. 

A common little helper ingredient that helps water and oil to mix together, aka emulsifier.

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. 

What-it-does: emollient

We don't have description for this ingredient yet.

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.

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

A nice odorless liquid used mainly as a superior solubilizer and efficacy booster for cosmetic active ingredients such as skincare bigshot vitamin C, self-tanning active DHA or the anti-acne gold standard, benzoyl peroxide

Other than that it can also be used in hair care products where it gives a longer-lasting and more uniform coloring. According to a manufacturer, it might even prevent the formation of split ends.

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". 

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

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

Mannose is one of the many sugar molecules out there and similar to the other ones, it works as a great humectant and moisturizer in cosmetic products. 

Also-called: apalight | What-it-does: abrasive/scrub, emulsion stabilising

Hydroxyapatite is a mineral found naturally in our bones and teeth. As for cosmetics, it is claimed to act as a sunscreen booster as well as a soft-focus agent

What-it-does: antioxidant, chelating

We don't have description for this ingredient yet.

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

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

What-it-does: antioxidant

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

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 >>

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. 

Also-called: Cetearyl Octanoate | What-it-does: emollient

A synthetic emollient oil that leaves a soft non-greasy, non-sticky feel on the skin, absorbs fast and can be emulsified (mixed with water) very easily. 

Also-called: Cromollient | What-it-does: emollient, surfactant/cleansing

We don't have description for this ingredient yet.

Linoleic Acid - goodie
Also-called: LA, omega-6 fatty acid, 18:2 cis-9,12, Form of Vitamin F | What-it-does: skin-identical ingredient, emollient, surfactant/cleansing

The famous omega-6 fatty acid, the mother of all ω-6 fatty acids in our body. It is a so-called polyunsaturated fatty acid meaning it has more than one (in this case two) double bonds and a somewhat kinky structure that makes LA and LA-rich oils a thin liquid.

It is also an essential fatty acid meaning our body cannot synthesize it and has to take it from food. This is not hard at all as plenty of nuts (such as flax, poppy or sesame seeds) and vegetable oils (such as sunflower or safflower) are rich in LA. The hard thing seems to be eating enough omega-3-s, more specifically eating a healthy ratio of omega-6 to omega-3, but that is a topic for a what-is-good-to-eat-site and not for us. 

Ferulic Acid - goodie

Ferulic Acid (FA) is a goodie that can be found naturally in plant cell walls. There is a lot of it especially in the bran of grasses such as rice, wheat and oats. 

FA - whose main job is to be an antioxidant - owes its fame to a 2005 research that discovered that adding in 0.5% FA to a 15% Vitamin C + 1% Vitamin E solution not only stabilizes the highly unstable, divaish Vit C, but it also doubles the photoprotection abilities of the formula. 

Also-called: Soybean Sterols | What-it-does: emollient

We don't have description for this ingredient yet.

Phospholipids - goodie

A type of lipid that's the major (about 75%) component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient.

It has a water-loving head with two water-hating tails and this structure gives the molecule emulsifying properties. It is also often used to create liposomes, small spheres surrounded by phospholipid bi-layer designed to carry some active ingredient and help its absorption.

We don't have description for this ingredient yet.

Ectoin - goodie

Ectoin is a surprisingly well-researched, multi-functional active that can do from pollution & light protection to skin hydration, soothing, and barrier repair, several things to your skin. 

It is an extremolyte, a small stress-protection molecule that protects microorganisms living under extreme conditions such as salt lakes, hot springs, arctic ice, the deep sea, or deserts. It was discovered in 1985 in a microorganism living in a salt lake in the Egyptian desert. 

What-it-does: antioxidant

We don't have description for this ingredient yet.

Retinol - superstar
Also-called: Vitamin A, Form of Retinoids | What-it-does: cell-communicating ingredient
  • Retinol (pure Vitamin A) is probably the most proven anti-aging ingredient available OTC
  • It has to be converted in the skin to retinoic acid to work its magic
  • Once converted, it has the same effect as all-trans-retinoic acid, aka tretinoin
  • A generally accepted ballpark number is that retinol is 10-to-20 times less potent than retinoic acid
  • It makes skin less wrinkled, smoother, firmer and tighter
  • It might also be helpful for acne prone skin as it normalizes keratinization and makes the pores produce less sebum
  • Possible side effects and irritation are also much less than with retinoic acid
  • Do not use whilst pregnant
Read all the geeky details about Retinol here >>

What-it-does: antioxidant

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.

We don't have description for this ingredient yet.

Also-called: Maris Aqua | What-it-does: moisturizer/humectant, solvent

We don't have description for this ingredient yet.

If you ever wondered what those little Listerine breath strips were made of, you found your answer! Pullulan is a polysaccharide polymer, which basically means that it’s a big molecule made up of smaller sugar molecule units.

It dissolves in water and can make a thin, elastic, and moisture-absorbing film when spread on the skin that can cause an instant tightening effect. It can also be used as a thickener to get a silicone-like feel and can be used in peel-off masks. Btw, it's made from fungus via fermentation. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Also-called: Horsetail Kelp Extract

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant

A 100% natural and plant-derived moisturizer that mimics the natural carbohydrate fraction found in the upper layer of the skin. Its special magic power is to bind to the skin stronger and longer than other moisturizer ingredients do so it can keep the skin hydrated longer than usual.

Also-called: Baker's Yeast | What-it-does: moisturizer/humectant

Saccharomyces cerevisiae (SC)  is the fancy name for common baker’s yeast. 

Usually different kind of yeast extracts are used in skincare for their great hydrating, and general skin conditioning properties. We could find one research paper to back this up: It has found that SC indeed increases skin moisture and had improved skin microrelief (the small wrinkles and surface irregularities of skin). 

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

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

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

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

It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 

Bakuchiol - goodie
Also-called: Sytenol A, Phyto Retinol | What-it-does: cell-communicating ingredient, antioxidant, antimicrobial/antibacterial

At first glance, you could think that Bakuchiol is your average plant extract. It is derived from the seeds of Psoralea Corylifolia, aka Babchi, a plant important in Indian and Chinese medicine. The molecule was first isolated in 1973 and several anti-something properties are known about it: it has anti-inflammatory, antioxidant, anti-tumor, anti-bacterial and hepatoprotective magical abilities like plenty of other Ayurvedic plant extracts.

What makes Bakuchiol a special snowflake is the recent discovery that it behaves on the skin in a way very similar to well-known skincare superstar, retinol. While chemically, it has nothing to do with the vitamin-A family, aka retinoids, comparative gene expression profiling (a fancy way of saying that they compared how retinol and bakuchiol modify the way  skin cells behave and produce important skin proteins such as collagen) shows that retinol and bakuchiol regulate skin cell behavior in a similar way. 

Isosorbide Dicaprylate (IDC) is a smart, oil-loving skin hydrator and barrier builder molecule. It works synergistically with glycerin as it up-regulates Aquaporin 3 (AQP3), an important transmembrane protein that transports our beloved friend glycerin, along with its’ hydrating groupie water molecules that surround it, into the cell. To put it more simply - AQP3 makes sure that glycerin and water are well distributed in the outer layer of the skin and thus the skin is well-hydrated. 

IDC is also claimed to upregulate the expression of CD44 (a hyaluronic acid binding receptor), ceramide synthase (an enzyme required for ceramide synthesis), and decrease transepidermal water loss (TEWL).

Alcohol - icky
Also-called: Ethanol | What-it-does: antimicrobial/antibacterial, solvent, viscosity controlling, astringent

Simply alcohol refers to ethanol and it's a pretty controversial ingredient. It has many instant benefits: it's a great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial. No wonder it's popular in toners and oily skin formulas. 

The downside is that it can be very drying if it's in the first few ingredients on an ingredient list. 

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

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

What-it-does: 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. 

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, 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

What-it-does: solvent, emulsifying, perfuming, surfactant/cleansing | Irritancy: 0-1 | Comedogenicity: 0-2

Similar to other glycols, it's a helper ingredient used as a solvent, or to thin out thick formulas and make them more nicely spreadable. 

Hexylene Glycol is also part a preservative blend named Lexgard® HPO, where it helps the effectiveness of current IT-preservative, phenoxyethanol

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.

Gluconolactone - superstar
What-it-does: exfoliant, chelating
  • It’s a polyhydroxy acid (PHA), that is often referred to as next generation AHA
  • It gently lifts off dead skin cells form the skin surface making skin smooth and even
  • In the long term it provides anti-aging benefits, like increased skin thickness and decreased wrinkles (though a tad less than even more proven superstar AHAs)
  • It’s a great moisturizer and even helps to repair impaired skin barrier
  • It’s antioxidant, and does not make your skin more sensitive to the sun
  • It can be used even if your skin is very sensitive, rosacea prone or if you are post cosmetic procedure
Read all the geeky details about Gluconolactone here >>

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

What-it-does: viscosity controlling, absorbent/mattifier | Irritancy: 0 | Comedogenicity: 0

A type of clay mineral that works as a nice helper ingredient to thicken and stabilize formulas. As a clay, it consists of platelets that have a negative charge on the surface (face) and a positive on the edge. So the face of one platelet attracts the edge of the other and this builds a so-called "house of card" structure meaning that Magnesium Aluminum Silicate (MAS) thickens up products and helps to suspend non-soluble particles such as color pigments or inorganic sunscreens (zinc oxide and titanium dioxide).

As the "house of card" structure takes some time to form but collapses quickly if the formula is stirred, products thickened with MAS can be thick in the jar but become easily spreadable upon application (called thixotropy). MAS also gives nice sensory properties, it is not tacky or sticky and gives a rich, creamy skin feel. Also a good team player and works in synergy with other thickeners such as Cellulose Gum or Xanthan Gum

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: chelating

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.

It is typically used in tiny amounts, around 0.1% or less.

BHA - icky
Also-called: Butylated Hydroxy Anisole | What-it-does: antioxidant, preservative

It's the acronym for Butylated Hydroxy Anisole. It's a synthetic antioxidant that's used as a preservative

It's a somewhat controversial ingredient: The U.S. National Institutes of Health says that BHA is "reasonably anticipated to be a human carcinogen based on evidence of carcinogenicity in experimental animals" (source: wikipedia). But, and this is a big but: these experiments were made on animals and BHA was used in high doses as part of their diet. There is no evidence that the same is true when used in tiny amounts in cosmetics products. So you probably have nothing to worry about, but if you are a better safe than sorry type there are plenty of nice products without BHA to choose from. :) 

Also-called: Butylated Hydroxy Toluene | What-it-does: antioxidant, preservative

It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.

There is some controversy around BHT. It's not a new ingredient, it has been used both as a food and cosmetics additive since the 1970s. Plenty of studies tried to examine if it's a carcinogen or not. This Truth in Aging article details the situation and also writes that all these studies examine BHT when taken orally.

Also-called: Sweet Orange Peel Oil, Citrus Sinensis Oil | What-it-does: perfuming

The essential oil coming from the rind of the orange (the sweet one). In general, the main component of citrus peel oils is limonene (83-97% for sweet orange peel), a super common fragrant ingredient that makes everything smell nice (but counts as a frequent skin sensitizer).

Other than that, citrus peel also contains the problematic compound called furanocoumarin that makes them mildly phototoxic. Orange peel contains less of it than some other citruses (like bergamot or lime), but still, be careful with it especially if it is in a product for daytime use.  

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

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

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

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.

Citral - icky
What-it-does: perfuming

It’s a common fragrance ingredient that smells like lemon and has a bittersweet taste.  It can be found in many plant oils, e.g. lemon, orange, lime or lemongrass. 

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

Geraniol - icky
What-it-does: perfuming

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

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

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 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 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 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
A fast spreading emollient ester (hexyl alcohol + lauric acid) that's used in water in oil emulsions or in water-free formulas. It gives a light skin feel. 
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 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 | viscosity controlling
irritancy, com. 0, 2-3
A common multi-tasker fatty acid that works as an emollient, thickener and emulsion stabilizer. [more]
what‑it‑does emollient | emulsifying
irritancy, com. 0, 1
Waxy, white, solid stuff that helps water and oil to mix together and leaves the skin feeling soft and smooth. [more]
what‑it‑does surfactant/cleansing | emulsifying
irritancy, com. 0, 0
A commonly used water-soluble surfactant and emulsifier. [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 2, 2
A fatty (the good, non-drying kind of) alcohol that makes your skin feel smooth and nice (emollient), helps to thicken up products and also helps water and oil to blend (emulsifier).
what‑it‑does emulsifying
irritancy, com. 1, 0
A popular, vegetable-derived oil-loving emulsifier that helps water to mix with oil. In itself, it is suitable for water-in-oil emulsions (where water droplets are dispersed in oil), but it is more often used as a co-emulsifier next to other, water-loving emulsifiers.  Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the fatty [more]
what‑it‑does emulsifying | surfactant/cleansing
A common little helper ingredient that helps water and oil to mix together, aka emulsifier.
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 emollient
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 solvent | moisturizer/humectant | perfuming
irritancy, com. 0, 0
A nice odorless liquid used mainly as a superior solubilizer and efficacy booster for cosmetic active ingredients such as vitamin C or benzoyl peroxide. [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 moisturizer/humectant
what‑it‑does moisturizer/humectant
A sugar molecule that works as a great humectant and moisturizer in cosmetic products.  [more]
what‑it‑does abrasive/scrub
Hydroxyapatite is a mineral found naturally in our bones and teeth. As for cosmetics, it is claimed to act as a sunscreen booster as well as a soft-focus agent.  [more]
what‑it‑does antioxidant | chelating
what‑it‑does moisturizer/humectant
A type of sugar molecule, that has water-binding properties and helps to keep your skin hydrated.  [more]
what‑it‑does antioxidant
what‑it‑does moisturizer/humectant
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 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 emollient
A synthetic emollient oil that leaves a soft non-greasy, non-sticky feel on the skin, absorbs fast and can be emulsified (mixed with water) very easily.  [more]
what‑it‑does emollient | surfactant/cleansing
what‑it‑does skin-identical ingredient | emollient | surfactant/cleansing
The famous omega-6 fatty acid, the mother of all ω-6 fatty acids in our body. It is a so-called polyunsaturated fatty acid meaning it has more than one (in this case two) double bonds and a somewhat kinky structure that makes LA and LA-rich oils a thin liquid.It is also an essential fatty acid meaning our body cannot synthesize  [more]
what‑it‑does antioxidant | antimicrobial/antibacterial
A great antioxidant that is most famous for stabilizing the highly unstable Vitamin C. It also doubles the photoprotection abilities of Vit C+E formulas. [more]
what‑it‑does emollient
what‑it‑does skin-identical ingredient | emollient
A type of lipid that's the major component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient. It's also often used to create liposomes. [more]
what‑it‑does antioxidant | soothing | moisturizer/humectant
Ectoin is a surprisingly well-researched, multi-functional active that can do from pollution & light protection to skin hydration, soothing, and barrier repair, several things to your skin. It is an extremolyte, a small stress-protection molecule that protects microorganisms living under extreme conditions such as  [more]
what‑it‑does antioxidant
what‑it‑does cell-communicating ingredient
Vitamin A - the most proven anti-aging ingredient available OTC that can smooth wrinkles and make skin firmer. It might also be useful for acne-prone skin as it normalizes keratinization. [more]
what‑it‑does antioxidant
what‑it‑does moisturizer/humectant | solvent
If you ever wondered what those little Listerine breath strips were made of, you found your answer! Pullulan is a polysaccharide polymer, which basically means that it’s a big molecule made up of smaller sugar molecule units. It dissolves in water and can make a thin, elastic, and moisture-absorbing film when spread on the skin that can cause an instant tightening effect. [more]
what‑it‑does moisturizer/humectant
A natural moisturizer that can bind to the skin stronger and longer than other similar ingredients so it can keep the skin hydrated longer than usual. [more]
what‑it‑does moisturizer/humectant
Saccharomyces cerevisiae (SC)  is the fancy name for common baker’s yeast.  Usually different kind of yeast extracts are used in skincare for their great hydrating, and general skin conditioning properties. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
The thing in the pee that is also a natural moisturizing factor (NMF) with mild keratolytic and strong skin moisturizing superpowers. [more]
what‑it‑does emulsifying | surfactant/cleansing
irritancy, com. 0, 0
It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 
what‑it‑does cell-communicating ingredient | antioxidant | antimicrobial/antibacterial
At first glance, you could think that Bakuchiol is your average plant extract. It is derived from the seeds of Psoralea Corylifolia, aka Babchi, a plant important in Indian and Chinese medicine. [more]
what‑it‑does cell-communicating ingredient | moisturizer/humectant
Isosorbide Dicaprylate (IDC) is a smart, oil-loving skin hydrator and barrier builder molecule. It works synergistically with glycerin as it up-regulates Aquaporin 3 (AQP3), an important transmembrane protein that transports our beloved friend glycerin, along with its’ hydrating groupie water molecules that surround it, into the cell. [more]
what‑it‑does antimicrobial/antibacterial | solvent | viscosity controlling
Simple alcohol that's a great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent, and antimicrobial. In large amount can be very drying. [more]
what‑it‑does emollient | emulsifying
It's quite the multi-tasker: an emollient and water-binding ingredient but also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes.  [more]
what‑it‑does 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 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 solvent | emulsifying | perfuming | surfactant/cleansing
irritancy, com. 0-1, 0-2
Similar to other glycols, it's a helper ingredient used as a solvent, or to thin out thick formulas and make them more nicely spreadable.  Hexylene Glycol is also part a preservative blend named Lexgard® [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]
what‑it‑does exfoliant | chelating
A next generation AHA, a so-called PHA that gently exfoliates skin without irritation. It also moisturizes and helps the skin barrier. It also has antioxidant properties. [more]
what‑it‑does moisturizer/humectant
what‑it‑does viscosity controlling
irritancy, com. 0, 0
A type of clay mineral that works as a nice helper ingredient to thicken and stabilize formulas. As a clay, it consists of platelets that have a negative charge on the surface (face) and a positive on the edge. [more]
what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does chelating
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 antioxidant | preservative
It's the acronym for Butylated Hydroxy Anisole. It's a synthetic antioxidant that's used as a preservative.  It's a somewhat controversial ingredient: The U.S. National Institutes of Health says that BHA is "reasonably anticipated to be a human carcinogen based on evidence of carcinogenicity in experimental animals" [more]
what‑it‑does antioxidant | preservative
It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.There is some controversy around BHT. [more]
what‑it‑does perfuming
The essential oil coming from the rind of the orange. Its main component (83-97%) is limonene, the super common fragrant ingredient. [more]
what‑it‑does perfuming | solvent
A super common fragrance ingredient found naturally in many plants including citrus peel oils, rosemary or lavender. It autoxidizes on air exposure and counts as a common skin sensitizer. [more]
what‑it‑does perfuming
A super common fragrance ingredient that can be found among others in lavender, ylang-ylang, bergamot or jasmine. The downside of it is that it oxidises on air exposure and might become allergenic. [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like lemon. [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like rose and can be found in rose oil. [more]