|Ingredient name||what-it-does||irr., com.||ID-Rating|
|Hydrolyzed Collagen||emollient, moisturizer/humectant||goodie|
|Sodium Hyaluronate||skin-identical ingredient, moisturizer/humectant||0, 0||goodie|
|Polysorbate 20||emulsifying||0, 0|
|Palmitoyl Pentapeptide 3||cell-communicating ingredient||goodie|
Dr Sebagh Serum RepairIngredients explained
Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product.
It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water.
Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying.
One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time.
The chemically chopped up version of the big protein molecule, collagen. It is often derived from fish or bovine sources and works as a nice moisturizer and humectant that helps the skin to hold onto water.
To understand a bit more what Hydrolyzed Collagen is, you have to know that proteins are large chains of amino acids connected with so called-peptide bonds. These bonds can be broken up when a water molecule is added and the resulting thing is a mix of shorter length amino acids, also called peptides. So Hydrolyzed Collagen is not really collagen, it is rather an undefined and varying mix of largish peptides. Based on a manufacturer's data, the whole, soluble collagen has an average molecular weight of 300 000 Da, while this chopped up mixture has an average MW of 12 000 Da (still pretty big).
The main thing of these largish peptides is to act as water-binding agents, and to make the skin nice and smooth (aka emollient). Hydrolyzed Collagen is also often used in cleansers as it can make harsh surfactants milder and in hair conditioners as it improves the flexibility and manageability of hair.
If you wanna know more about collagen in cosmetics, we have a shiny explanation about soluble collagen here >>
It’s the - sodium form - cousin of the famous NMF, hyaluronic 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".
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).
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.
A pretty famous and better-researched peptide consisting of five amino acids (the building blocks of all proteins). It was created in a joint effort by the French ingredient supplier, Sederma and the cosmetics industry big shot, Procter&Gamble.
The amino acid sequence of the peptide is lysine–threonine–threonine–lysine–serine (KTTKS). Sometimes, it's also called collagen pentapeptide, as it's a subfragment of skin-structure-giving type I collagen. The KTTKS amino sequence is then attached for better oil solubility and skin penetration to palmitic acid and BOOM; we get Palmitoyl Pentapeptide-4.
Though most research is manufacturer sponsored, the clinical studies about Palmitoyl Pentapeptide-4 are promising. In short, it can reduce fine lines, wrinkles and improve skin texture significantly (and at crazy low concentrations, the studies were done with just 3 ppm that is 0.0003%).
There are also studies comparing Palmitoyl Pentapeptide-4 with anti-aging gold standard, retinol. One of them compared 3ppm Pal-KTTKS with 700 ppm (0.07%) retinol and found that they showed similar wrinkle improving ability with the peptide showing better skin tolerability.
Bottom line, if you are into peptides, this is a good one to try.
It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.
It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic.
Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10).
It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.
The most common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon.
Apart from the general controversy around parabens (we wrote about it more here), there is a 2006 in-vitro (made in the lab not on real people) research about methylparaben (MP) showing that when exposed to sunlight, MP treated skin cells suffered more harm than non-MP treated skin cells. The study was not done with real people on real skin but still - using a good sunscreen next to MP containing products is a good idea. (Well, in fact using a sunscreen is always a good idea. :))
A very common type of feared-by-everyone-mostly-without-scientific-reason paraben. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon. Read more about parabens here >>
A very common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon.
This totally unpronounceable ingredient (let’s take a shortcut: MCI) is a super effective preservative with both antibacterial and antifungal effects that works at very low concentrations.
The bad news with it though is that it can sensitize the skin easily (it’s a so-called non-fragrance allergen). It’s not permitted to be used alone, but only with its BFF, methylisothiazolinone (MI), another icky preservative. Together they have a broad spectrum antimicrobial effect but are permitted to be used only in rinse-off products (under 0.0015%).
As you may guess, if something is only recommended in products that you rinse off (cleansers and shampoos), then it’s probably not the best ingredient for the skin.
Methylisothiazolinone (MI) is a preservative that' super efficient against bacteria at surprisingly low concentrations. The problem with it though is that it can also sensitize and irritate the skin quite easily when it comes in leave-on formulas.
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