Follow us on our new Insta page »
Peter Thomas Roth Potent C Targeted Spot Brightener

Potent C Targeted Spot Brightener

Peter Thomas Roth Potent-C Targeted Spot Brightener is 50x more powerful than traditional vitamin C. Formulated with gwennis, an active algae extract proven to reduce the appearance of the size of dark spots up to 75%.
Uploaded by: manu on 09/07/2019

Peter Thomas Roth Potent C Targeted Spot Brightener
Ingredients explained

Also-called: Aqua;Water | What-it-does: solvent

Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product. 

It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water. 

Expand to read more

Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying. 

One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time. 

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

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

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

Expand to read more

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

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

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

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

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

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

What-it-does: emulsifying

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant, solvent | Irritancy: 0 | Comedogenicity: 1

Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.  

BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.

Expand to read more

It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive. 

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

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

An extremely common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams and lotions. It also helps to stabilize oil-water mixes (emulsions), though it does not function as an emulsifier in itself. Its typical use level in most cream type formulas is 2-3%.  

It’s a so-called fatty alcohol, a mix of cetyl and stearyl alcohol, other two emollient fatty alcohols.  Though chemically speaking, it is alcohol (as in, it has an -OH group in its molecule), its properties are totally different from the properties of low molecular weight or drying alcohols such as denat. alcohol. Fatty alcohols have a long oil-soluble (and thus emollient) tail part that makes them absolutely non-drying and non-irritating and are totally ok for the skin.

Also-called: Vitamin E Acetate | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 0

It’s the most commonly used version of pure vitamin E in cosmetics. You can read all about the pure form here. This one is the so-called esterified version. 

According to famous dermatologist, Leslie Baumann while tocopheryl acetate is more stable and has a longer shelf life, it’s also more poorly absorbed by the skin and may not have the same awesome photoprotective effects as pure Vit E. 

What-it-does: emollient, emulsifying | Irritancy: 0 | Comedogenicity: 1-2

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.

Expand to read more

It also occurs naturally in our body and is used as a food additive. As cosmetic chemist Colins writes it, "its safety really is beyond any doubt".

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.

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. 

Expand to read more

Couple of other studies show that FA just by itself is also a nice addition to cosmetic formulations: it can penetrate the skin (which is kind of important to do the job) and it has protecting properties against UV caused skin damage.

So if you spot it on the ingredient list be happy about it. :)

What-it-does: emollient | Irritancy: 1 | Comedogenicity: 3-4

A clear, colorless emollient ester (oily liquid from isopropyl alcohol + palmitic acid) that makes the skin nice and smooth. It has very good spreading properties and gives a silky touch to the products.

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 >>

What-it-does: emulsifying, surfactant/cleansing | Irritancy: 3 | Comedogenicity: 2

A common functional ingredient that helps to keep the oil-loving and water-loving ingredients together (emulsifier), stabilizes and thickens the products. 

Chemically speaking, it is ethoxylated Cetearyl alcohol, meaning that some ethylene oxide is added to the fatty alcohol to increase the water-soluble part in the molecule. The result is that the mainly oil soluble, emollient fatty alcohol is converted to an emulsifier molecule that keeps oil and water mixed in creams. The number in the name of Ceteareth emulsifiers refers to the average number of ethylene oxide molecules added and 20 makes a good 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. 

Expand to read more

As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types). 

Allantoin - goodie
What-it-does: soothing | Irritancy: 0 | Comedogenicity: 0

Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. 

It's not only soothing but it' also skin-softening and protecting and can promote wound healing.

Also-called: Aloe Vera | What-it-does: soothing, moisturizer/humectant

Aloe Vera is one of today’s magic plants. It does have some very nice properties indeed, though famous dermatologist Leslie Baumann warns us in her book that most of the evidence is anecdotal and the plant might be a bit overhyped.

What research does confirm about Aloe is that it’s a great moisturizer and has several anti-inflammatory (among others contains salicylates, polysaccharides, magnesium lactate and C-glucosyl chromone) as well as some antibacterial components. It also helps wound healing and skin regeneration in general. All in all definitely a goodie. 

We don't have description for this ingredient yet.

What-it-does: emollient

We don't have description for this ingredient yet.

Citric Acid - goodie
What-it-does: exfoliant, 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. 

Expand to read more

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: 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.

What-it-does: sunscreen

Titanium Dioxide is one of the two members of the elite sunscreen group called physical sunscreens (or inorganic sunscreens if you’re a science geek and want to be precise).

Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).

Expand to read more

Anyway, it doesn't matter if it reflects or absorbs, Titanium Dioxide is a pretty awesome sunscreen agent for two main reasons: it gives a nice broad spectrum coverage and it's highly stable. Its protection is very good between 290 - 350 nm (UVB and UVA II range), and less good at 350-400 nm (UVA I) range. Regular sized Titanium Dioxide also has a great safety profile, it's non-irritating and is pretty much free from any health concerns (like estrogenic effect worries with some chemical filters).

The disadvantage of Titanium Dioxide is that it's not cosmetically elegant, meaning it's a white, "unspreadable" mess. Sunscreens containing Titanium Dioxide are often hard to spread on the skin and they leave a disturbing whitish tint. The cosmetic industry is, of course, really trying to solve this problem and the best solution so far is using nanoparticles. The itsy-bitsy Nano-sized particles improve both spreadability and reduce the whitish tint a lot, but unfortunately, it also introduces new health concerns. 

The main concern with nanoparticles is that they are so tiny that they are absorbed into the skin more than we want them (ideally sunscreen should remain on the surface of the skin). Once absorbed they might form unwanted complexes with proteins and they might promote the formation of evil free radicals. But do not panic, these are concerns under investigation. A 2009 review article about the safety of nanoparticles summarizes this, "to date, in-vivo and in-vitro studies have not demonstrated percutaneous penetration of nanosized particles in titanium dioxide and zinc oxide sunscreens". The English translation is, so far it looks like sunscreens with nanoparticles do stay on the surface of the skin where they should be.  

All in all, Titanium Dioxide is a famous sunscreen agent and for good reason, it gives broad spectrum UV protection (best at UVB and UVA II), it's highly stable, and it has a good safety profile. It's definitely one of the best UV-filter agents we have today, especially in the US where new-generation Tinosorb filters are not (yet) approved. 

Also-called: CI 77019

A super versatile and common mineral powder that comes in different particle sizes. It is a multi-tasker used to improve skin feel, increase product slip, give the product light-reflecting properties, enhance skin adhesion or serve as an anti-caking agent.

It is also the most commonly used "base" material for layered composite pigments such as pearl-effect pigments. In this case, mica is coated with one or more metal oxides (most commonly titanium dioxide) to achieve pearl effect via the physical phenomenon known as interference. 

What-it-does: buffering

We don't have description for this ingredient yet.

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.

Expand to read more

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.

What-it-does: preservative

It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.

It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic. 

Expand to read more

Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10). 

It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.

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 emulsifying
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 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 emollient | viscosity controlling
irritancy, com. 1, 2
A super common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams. [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 | emulsifying
irritancy, com. 0, 1-2
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 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
irritancy, com. 1, 3-4
A clear, colorless emollient ester (oily liquid) that makes the skin nice and smooth. [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 emulsifying | surfactant/cleansing
irritancy, com. 3, 2
A common functional ingredient that helps to keep the oil-loving and water-loving ingredients together (emulsifier), stabilizes and thickens the products.  [more]
what‑it‑does emollient
irritancy, com. 0, 1
A very common silicone that gives both skin and hair a silky smooth feel. It also forms a protective barrier on the skin and fills in fine lines. Also used for scar treatment. [more]
what‑it‑does soothing
irritancy, com. 0, 0
Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. It's not only soothing but it' [more]
what‑it‑does soothing | moisturizer/humectant
The famous aloe vera. A great moisturizer and anti-inflammatory ingredient that also helps wound healing and skin regeneration. [more]
what‑it‑does emollient
what‑it‑does exfoliant | 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 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 sunscreen
A physical/inorganic sunscreen with pretty broad spectrum (UVB and UVA II, less good at UVA I) protection and good stability. Might leave some whitish tint on the skin, though. [more]
A mineral powder used to improve skin feel, increase product slip, give the product some light-reflecting properties, enhance skin adhesion or serve as an anti-caking agent. A real multi-tasker. [more]
what‑it‑does buffering
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]
what‑it‑does preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]