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This product has been discontinued. See the current version here.
Cosmedix Serum 16

Serum 16 (Discontinued)

This serum contains LG-Retinex — a proprietary encapsulation of retinol and retinaldehyde — that helps carry the active ingredients to where they need to be, for the best possible action. Great for normal to dry skin, this serum is ideal for imbalanced ageing skin, with concerns including crow's feet, fine lines and medium to deep wrinkles.
Uploaded by: girlbuysthings on

Skim through

Ingredient name what-it-does irr., com. ID-Rating
Aqua solvent
Hamamelis Virginiana (Witch Hazel) Water soothing goodie
Carthamus Tinctorius (Safflower) Seed Oil antioxidant, emollient 0, 0-2 goodie
Glycerin skin-identical ingredient, moisturizer/​humectant 0, 0 superstar
Sodium Lactate buffering, moisturizer/​humectant goodie
Sodium Acrylates Copolymer viscosity controlling
Phospholipids skin-identical ingredient, emollient goodie
Hydrogenated Polyisobutene emollient, viscosity controlling 2, 1
Polysorbate 20 emulsifying, surfactant/​cleansing 0, 0
Cetyl Alcohol emollient, viscosity controlling 2, 2
Retinol cell-communicating ingredient superstar
Retinal cell-communicating ingredient superstar
Proline (L) skin-identical ingredient goodie
Sodium Hyaluronate (L) skin-identical ingredient, moisturizer/​humectant 0, 0 goodie
Helianthus Annuus (Sunflower) Seed Oil emollient 0, 0 goodie
Tapioca Starch viscosity controlling
Leuconostoc/Radish Root Ferment Filtrate antimicrobial/​antibacterial, preservative
Lonicera Caprifolium (Honeysuckle) Flower Extract perfuming
Lonicera Japonica (Honeysuckle) Flower Extract soothing, antimicrobial/​antibacterial goodie
Santalum Austrocaledonicum (Sandalwood) Wood Oil perfuming
Lavandula Hybrida (Lavandin) Oil emollient
Galactoarabinan antioxidant goodie
Glycosaminoglycans emollient
Potassium Hydrolyzed Polygamma-Glutamate
Tocopherol (D-Alpha) antioxidant 0-3, 0-3 goodie
Squalane skin-identical ingredient, emollient 0, 1 goodie
Hydroxypropyl Starch Phosphate viscosity controlling
Dimethicone emollient 0, 1
Polyglyceryl-10 Stearate emulsifying
Lecithin emollient, emulsifying goodie
Xanthan Gum viscosity controlling
Tetrasodium EDTA chelating
Citric Acid buffering
Alcohol antimicrobial/​antibacterial, solvent, viscosity controlling icky
Potassium Sorbate preservative

Cosmedix Serum 16
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. 

What-it-does: soothing, astringent

The distillate created from different parts of the hazelnut-bush-like magic tree, commonly called Witch Hazel. Hamamelis Virginiana Water is a bit of a sloppy ingredient name as the leaves, the twigs and the bark can be used to create extracts or distillates and the different parts contain different amounts of biologically active components. But what you are getting is probably a nice water with astringent, soothing, antioxidant and antibacterial magic properties.  

We went into great detail about Witch Hazel in cosmetics here, detailing the main biologically active components and how they are different in different parts of the plant. Click here and read more >>

Also-called: Safflower Seed Oil | What-it-does: antioxidant, emollient | Irritancy: 0 | Comedogenicity: 0-2

The oil coming from the seeds of the yellow flowered safflower plant. Similar to other plant oils, it's loaded with nourishing and moisturizing fatty acids: it's a high linoleic acid oil (70%) and has only smaller amounts of oleic acid (11%) (this might be great for acne-prone skin). It also contains antioxidant vitamin E (44mg/100g alpha-tocopherol).

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 >>

The sodium salt of lactic acid. It's a great skin moisturizer and also used to regulate the pH value of the cosmetic formula. It's a natural ingredient approved by both ECOCERT and COSMOS.

What-it-does: viscosity controlling

A big molecule from repeated subunits that is used to form gel-like textures and create a film on the skin. 

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.

What-it-does: emollient, viscosity controlling | Irritancy: 2 | Comedogenicity: 1

A synthetic liquid oil that can replace mineral oil or silicone oils in the cosmetic formulas. There are different grades depending on the molecular weight ranging from very light, volatile, non-residue leaving ones to more substantial, slight residue leaving ones.

Apart from leaving the skin soft and smooth (emollient), it's also used as a waterproofing agent in sunscreens or makeup products and as a shine enhancer in lip gloss formulas. 

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. 

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.

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 >>

Retinal - superstar
Also-called: Form of Retinoids, Retinaldehyde | What-it-does: cell-communicating ingredient

If you are reading here, we are pretty sure the words retinoids and retinol ring a bell, but if not, you are seriously missing out, please click here immediately to catch up.  The TL;DR version is that retinoids are the royal family of skincare with tretinoin being the king, the only FDA-approved ingredient to treat the signs of photoaging. Retinol is like a grandkid, it has to be converted (through two steps) in the skin to become retinoic acid. The conversion means retinol is both less effective and less harsh on the skin. 

So where does our current molecule, Retinal, aka Retinaldehyde fit into the family (btw, here is a nice visual family tree about who is who)?  Remember that retinol needed two conversion steps to become retinoic acid? Yes, you are right, Retinal is the intermediate step between retinoic acid and retinol, meaning it needs only one conversion step to become active in the skin. If we go with our royal family analogy, Retinal is Prince William, directly next in line to the throne. 

Proline (L) - goodie

A non-essential amino acid (meaning that our body can produce it) that's also one of the major building blocks of collagen. According to the Futurederm blog, it might be able to improve wrinkles when combined with other amino acids, glycine and leucine

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". 

Also-called: Sunflower Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0

Sunflower does not need a big intro as you probably use it in the kitchen as cooking oil, or you munch on the seeds as a healthy snack or you adore its big, beautiful yellow flower during the summer - or you do all of these and probably even more. And by even more  we mean putting it all over your face as sunflower oil is one of the most commonly used plant oils in skincare.

It’s a real oldie: expressed directly from the seeds, the oil is used not for hundreds but thousands of years. According to The National Sunflower Association, there is evidence that both the plant and its oil were used by American Indians in the area of Arizona and New Mexico about 3000 BC. Do the math: it's more than 5000 years – definitely an oldie.

What-it-does: viscosity controlling

A soft, white powder that can be used as a talc replacement in body powders or in pressed powders. It also has some oil absorbing properties and gives increased cushion and richness to emulsion-type formulas.  

Also-called: Fermented Radish Root | What-it-does: antimicrobial/antibacterial, preservative

It's an alternative, natural preservative that comes from radishes fermented with Leuconostoc kimchii, a lactic acid bacteria that has been used to make traditional Korean dish, kimchi. During the fermentation process, a peptide is secreted from the bacteria that has significant antimicrobial properties

It is one of the more promising natural preservatives that can be used even alone (recommended at 2-4%), but it's not as effective as more common alternatives, like parabens or phenoxyethanol

What-it-does: perfuming

We don't have description for this ingredient yet.

Also-called: Japanese Honeysuckle Flower Extract | What-it-does: soothing, antimicrobial/antibacterial

Lonicera Japonica, or Japanese Honeysuckle as normal people call it, is a white-flowered honeysuckle known for being a traditional Chinese medicine. Modern research confirms that the plant has a super complex chemical composition with more than 140 compounds identified with possible anti-inflammatory, antibacterial, antiviral, antioxidative and hepatoprotective activities.

As for Lonicera Japonica Flower Extract in skin care, it can have two main roles. The first one is being an anti-inflammatory and soothing ingredient, probably due to chlorogenic acid, a polyphenol thought to be the main bioactive component of the flower.

What-it-does: perfuming

We don't have description for this ingredient yet.

What-it-does: emollient

We don't have description for this ingredient yet.

What-it-does: antioxidant

Galactoarabinan is a natural polysaccharide (a big carbohydrate molecule) that comes from the Larch trees.

According to the manufacturer it can do all kinds of good in a formula: it can reduce trans-epidermal-water-loss (a fancy way of saying that it's moisturizing), improve the appearance of skin’s superficial fine lines, improve the uniformity and spreadability of a formulation and provides SPF enhancement. What's more it can also help to boost the efficacy of AHA exfoliants (while not boosting the irritation side effect). 

What-it-does: emollient

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Also-called: Vitamin E | What-it-does: antioxidant | Irritancy: 0-3 | Comedogenicity: 0-3
  • Primary fat-soluble antioxidant in our skin
  • Significant photoprotection against UVB rays
  • Vit C + Vit E work in synergy and provide great photoprotection
  • Has emollient properties
  • Easy to formulate, stable and relatively inexpensive
Read all the geeky details about Tocopherol here >>

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: viscosity controlling

We don't have description for this ingredient yet.

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: emulsifying

A vegetable-based, PEG-free ingredient whose job is to help water and oil to mix nicely together (emulsifier). It is created by attaching ten water-loving glycerin molecules with the oil-loving fatty acid, stearic acid. The result is a partly water- and partly oil-loving molecule that creates stable and smooth emulsions that are also cosmetically elegant. It also has some moisturizing and softening benefits for skin and hair.

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

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

A handy 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: buffering

Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA. 

So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh. 

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. 

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.

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 soothing
The distillate created from the hazelnut-bush-like magic tree, commonly called Witch Hazel. It might have astringent, soothing, antioxidant and antibacterial properties. [more]
what‑it‑does antioxidant | emollient
irritancy, com. 0, 0-2
Safflower Seed Oil - emollient plant oil with moisturizing fatty acids (linoleic: 70%, oleic: 11%) and antioxidant vitamin E (44mg/100g alpha-tocopherol). [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 buffering | moisturizer/humectant
The sodium salt of lactic acid. It's a great skin moisturizer and also used to regulate the pH value of the cosmetic formula. [more]
what‑it‑does viscosity controlling
A big molecule from repeated subunits that is used to form gel-like textures and create a film on the skin.  [more]
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 emollient | viscosity controlling
irritancy, com. 2, 1
A synthetic liquid oil that can replace mineral oil or silicone oils in the cosmetic formulas. There are different grades depending on the molecular weight ranging from very light, volatile, non-residue leaving ones to more substantial, slight residue leaving ones.Apart from leaving the skin soft and smooth (emollient), it' [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 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 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 cell-communicating ingredient
If you are reading here, we are pretty sure the words retinoids and retinol ring a bell, but if not, you are seriously missing out, please click here immediately to catch up.  The TL;DR version is that retinoids are the royal family of skincare with tretinoin being the king, the only FDA-approved ingredient to treat the signs of photoaging. [more]
what‑it‑does skin-identical ingredient
A non-essential amino acid (meaning that our body can produce it) that might be able to improve wrinkles combined with other amino acids, glycine and leucine. [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 emollient
irritancy, com. 0, 0
Sunflower Oil - it's a great emollient that protects & enhances the skin barrier. [more]
what‑it‑does viscosity controlling
A soft, white powder that can be used as a talc replacement in body powders or in pressed powders. It also has some oil absorbing properties and gives increased cushion and richness to emulsion-type formulas.  
what‑it‑does antimicrobial/antibacterial | preservative
It's an alternative, natural preservative that comes from radishes fermented with Leuconostoc kimchii, a lactic acid bacteria that has been used to make traditional Korean dish, kimchi. [more]
what‑it‑does perfuming
what‑it‑does soothing | antimicrobial/antibacterial
Lonicera Japonica, or Japanese Honeysuckle as normal people call it, is a white-flowered honeysuckle known for being a traditional Chinese medicine. Modern research confirms that the plant has a super complex chemical composition with more than 140 compounds identified with possible anti-inflammatory, antibacterial, antiviral, antioxidative and hepatoprotective activities. [more]
what‑it‑does perfuming
what‑it‑does emollient
what‑it‑does antioxidant
Galactoarabinan is a natural polysaccharide (a big carbohydrate molecule) that comes from the Larch trees.According to the manufacturer it can do all kinds of good in a formula: [more]
what‑it‑does emollient
what‑it‑does antioxidant
irritancy, com. 0-3, 0-3
Pure Vitamin E. Great antioxidant that gives significant photoprotection against UVB rays. Works in synergy with Vitamin C. [more]
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 viscosity controlling
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 emulsifying
A vegetable-based, PEG-free ingredient whose job is to help water and oil to mix nicely together (emulsifier). It is created by attaching ten water-loving glycerin molecules with the oil-loving fatty acid, stearic acid. [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 viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does chelating
A helper ingredient that helps to neutralize 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 buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [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 preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]