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Acnemy Postzit Serum

Postzit Serum

This serum is based on glycolic acid that minimizes post-pimple marks (hyperpigmentation), improves skin texture and unifies skin tone.
Uploaded by: evi00 on

Acnemy Postzit 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. 

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. 

Niacinamide - superstar
Also-called: vitamin B3, nicotinamide | What-it-does: cell-communicating ingredient, skin brightening, anti-acne, moisturizer/humectant
  • A multi-functional skincare superstar with several proven benefits for the skin
  • Great anti-aging, wrinkle smoothing ingredient used at 4-5% concentration
  • Fades brown spots alone or in combination with amino sugar, acetyl glucosamine
  • Increases ceramide synthesis that results in a stronger, healthier skin barrier and better skin hydration
  • Can help to improve several skin conditions including acne, rosacea, and atopic dermatitis
Read all the geeky details about Niacinamide here >>

A derivative of clinically proven, superstar ingredient Azelaic Acid and hydrating amino acid Glycine. Azelaic acid is an awesome ingredient with anti-inflammatory, skin lightening and anti-acne effects, but its insolubility (it's soluble neither in water nor in oil) makes it difficult to use it in a cosmetically elegant and versatile way. 

The solution is supposed to be Potassium Azeloyl Diglycinate, at least according to the manufacturer. The derivative is very water soluble, easy to use in nice formulas and inherits all the lovely properties of Azelaic acid. It acts as a skin brightening agent via Tyrosinase (a famous enzyme needed to make melanin) inhibition and also has significant sebum normalizing activity. 

Regarding research, we could find two studies where Potassium Azeloyl Diglycinate's name popped up. One study examined the management of rosacea and the other one researched the treatment of melasma. Both were successful (we mean people showed improvement :)) but our Azelaic acid derivative was combined with other actives so it's hard to know what to attribute to this guy only. 

Overall, a promising multi-function active that's worth checking out if you have pigmentation-prone, acne-prone or rosacea-prone skin.

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 >>

We don't have description for this ingredient yet.

Glycolic Acid - superstar
What-it-does: exfoliant, buffering
  • It’s the most researched AHA with the most proven skin benefits
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It can help skin’s own collagen production that results in firmer, younger skin
  • It can fade brown spots caused by sun damage or PIH
  • 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)
  • Slight stinging or burning with a stronger AHA product is normal
  • If your skin is very sensitive, rosacea prone choose rather a BHA or PHA product
Read all the geeky details about Glycolic Acid here >>

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

Ceramide NP - goodie
Also-called: Ceramide 3 | What-it-does: skin-identical ingredient

One of the many types of ceramides that can be found naturally in the upper layer of the skin. Ceramides make up about 50% of the goopy stuff that's between our skin cells and play a super important role in having a healthy skin barrier and keeping the skin hydrated. It works even better when combined with its pal, Ceramide 1.

We wrote way more about ceramides at ceramide 1, so click here to know more.

It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range. 

Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415). 

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

A big molecule created from repeated subunits (a polymer of acrylic acid) that magically converts a liquid into a nice gel formula.  It usually has to be neutralized with a base (such as sodium hydroxide) for the thickening to occur and it creates viscous, clear gels that also feel nice and non-tacky on the skin. No wonder, it is a very popular and common ingredient. Typically used at 1% or less in most formulations.

What-it-does: emulsifying

We don't have description for this ingredient yet.

What-it-does: emulsifying

We don't have description for this ingredient yet.

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

It's one of the important lipids that can be found naturally in the outer layer of the skin. About 25% of the goopy stuff between our skin cells consists of cholesterol. Together with ceramides and fatty acids, they play a vital role in having a healthy skin barrier and keeping the skin hydrated. 

Apart from being an important skin-identical ingredient, it's also an emollient and stabilizer

A vegetable origin (coconut or palm kernel oil and glucose) cleansing agent with great foaming abilities. It's also mild to the skin and readily biodegradable.

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

Tocopherol - goodie
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 >>

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: buffering | Irritancy: 0 | Comedogenicity: 2

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

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

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

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

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

Also-called: Salt | What-it-does: viscosity controlling

Sodium chloride is the fancy name of salt. Normal, everyday table salt

If (similar to us) you are in the weird habit of reading the label on your shower gel while taking a shower, you might have noticed that sodium chloride is almost always on the ingredient list. The reason for this is that salt acts as a fantastic thickener in cleansing formulas created with ionic cleansing agents (aka surfactants) such as Sodium Laureth Sulfate. A couple of percents (typically 1-3%) turns a runny surfactant solution into a nice gel texture.

If you are into chemistry (if not, we understand, just skip this paragraph), the reason is that electrolytes (you know, the Na+ and Cl- ions) screen the electrostatic repulsion between the head groups of ionic surfactants and thus support the formation of long shaped micelles (instead of spherical ones) that entangle like spaghetti, and viola, a gel is formed. However, too much of it causes the phenomenon called "salting out", and the surfactant solution goes runny again. 

Other than that, salt also works as an emulsion stabilizer in water-in-oil emulsions, that is when water droplets are dispersed in the outer oil (or silicone) phase. And last but not least, when salt is right at the first spot of the ingredient list (and is not dissolved), the product is usually a body scrub where salt is the physical exfoliating agent

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. 

There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin. 

But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation. 

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. 

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: 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.

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

What-it-does: preservative

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

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

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 cell-communicating ingredient | skin brightening | anti-acne | moisturizer/humectant
A multi-functional skincare superstar that has clinically proven anti-aging, skin lightening, anti-inflammatory and barrier repair properties. [more]
what‑it‑does skin brightening | anti-acne | soothing
A mult-functional Azelaic acid derivative with skin brightening, anti-inflammatory and possibly some sebum regulating and anti-acne properties. [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 exfoliant | buffering
The most researched and well-known AHA exfoliant. It gently lifts off dead skin cells to reveal newer, fresher, smoother skin. In larger concentration (>10%) it's a proven collagen booster. [more]
what‑it‑does exfoliant | anti-acne | soothing | preservative
One of the gold standard ingredients for treating problem skin. It can exfoliate skin both on the surface and in the pores and it's a potent anti-inflammatory agent. [more]
what‑it‑does skin-identical ingredient
Ceramides make up 50% of the goopy stuff that's between our skin cells and play a super important role in having a healthy skin barrier and keeping the skin hydrated.  [more]
what‑it‑does viscosity controlling | emulsifying | surfactant/cleansing
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does viscosity controlling
irritancy, com. 0, 1
A handy white powder that magically converts a liquid into a nice gel formula. [more]
what‑it‑does emulsifying
what‑it‑does emulsifying
what‑it‑does skin-identical ingredient | emollient
irritancy, com. 0, 0
It's one of the important lipids that can be found naturally in the outer layer of the skin. About 25% of the goopy stuff between our skin cells consists of cholesterol. [more]
what‑it‑does surfactant/cleansing
A vegetable origin (coconut or palm kernel oil and glucose) cleansing agent with great foaming abilities. It's also mild to the skin and readily biodegradable.
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 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 moisturizer/humectant
A type of sugar molecule, that has water-binding properties and helps to keep your skin hydrated.  [more]
what‑it‑does buffering
irritancy, com. 0, 2
Helps to set the pH of a cosmetic formulation to be right. It’s very alkaline. [more]
what‑it‑does viscosity controlling
Sodium chloride is the fancy name of salt. Normal, everyday table salt.  If (similar to us) you are in the weird habit of reading the label on your shower gel while taking a shower, you might have noticed that sodium chloride is almost always on the ingredient list. [more]
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 preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]
what‑it‑does preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]