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Peter Thomas Roth Pro Strength 10% Pha Exfoliating Clarifying Liquid

Pro Strength 10% Pha Exfoliating Clarifying Liquid

An expert-level, daily leave-on exfoliating and clarifying liquid with 10 percent gluconolactone (PHA), five percent glycolic acid (AHA), and 0.5% salicylic acid (BHA).
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Peter Thomas Roth Pro Strength 10% Pha Exfoliating Clarifying Liquid
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. 

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 >>

A water-soluble, colorless, odorless humectant liquid that makes your skin nice and smooth (aka emollient) and gives a dry, non-tacky skin feel. It also has great instant and some longer-lasting moisturizing effect and works in synergy with fellow moisturizer, sorbitol

Also-called: lye | What-it-does: buffering

The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right. 

For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.  

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 >>

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 >>

Lactic Acid - superstar
  • It’s the second most researched AHA after glycolic acid
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It also has amazing skin hydrating properties
  • In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
  • 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)
Read all the geeky details about Lactic Acid here >>

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: emulsifying

A water-loving emollient that is used as a solubilizer in water-based, toner-like formulas. Solubilizers are handy helper ingredients to dissolve small amounts of oil-loving materials (such as essential oils or fragrances) into watery liquids. Polyglyceryl-4 Caprate also has some emollient properties, making the skin feel nice and smooth. 

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 >>

Also-called: LHA | What-it-does: exfoliant

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.

What-it-does: emollient

We don't have description for this ingredient yet.

Also-called: Form of Vitamin C | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 2

A form of skincare superstar, vitamin C. Even though we are massive vitamin C fans,  Ascorbyl Palmitate  (AP) is our least favorite. (Btw, if you do not know what the big deal with vitamin C is then you are missing out. You must go and read our geeky details about it.) 

So, AP is one of the attempts by the cosmetics industry to solve the stability issues with vitamin C while preserving its benefits,  but it seems to fall short on several things.

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 >>

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 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.

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

An Ecocert-approved, natural preservative that counts as gentle and non-irritating to the skin. Usually, it comes to the formula as part of a preservative blend as it's not enough on its own.

What-it-does: chelating, buffering

A little helper ingredient that is used to adjust the pH of the product. It also helps to keep products stay nice longer by neutralizing the metal ions in the formula (they usually come from water). 

What-it-does: emollient

We don't have description for this ingredient yet.

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.

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. 

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 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 solvent | moisturizer/humectant | emollient
A water-soluble, colorless, odorless humectant liquid that makes your skin nice and smooth (aka emollient) and gives a dry non-tacky skin feel. [more]
what‑it‑does buffering
Lye - A solid white stuff that’s very alkaline and used in small amount to adjust the pH of the product.  [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 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 exfoliant | moisturizer/humectant | buffering
A superstar AHA that not only exfoliates skin but is also a very good moisturizer. In higher concentration (10% and up) it can even improve skin firmness, thickness, and wrinkles. [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 emulsifying
A water-loving emollient that is used as a solubilizer in water-based, toner-like formulas. Solubilizers are handy helper ingredients to dissolve small amounts of oil-loving materials (such as essential oils or fragrances) into watery liquids. [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 exfoliant
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
what‑it‑does antioxidant
irritancy, com. 0, 2
An oil soluble vitamin C derivative that has mixed data about its effectiveness. [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 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
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
An Ecocert-approved, natural preservative that counts as gentle and non-irritating to the skin. Usually, it comes to the formula as part of a preservative blend as it's not enough on its own.
what‑it‑does chelating | buffering
A helper ingredient that is used to adjust the pH of the product. Also helps to keep products stay nice longer by neutralizing the metal ions in the formula. 
what‑it‑does emollient
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 preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]