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Peter Thomas Roth Instant Mineral Spf 45

Instant Mineral Spf 45

A transparent, matte mineral powder that provides on-the-go broad spectrum sun protection.
Uploaded by: abrooksmoyer on

Peter Thomas Roth Instant Mineral Spf 45
Ingredients explained

What-it-does: sunscreen, colorant

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).

What-it-does: sunscreen | Irritancy: 0 | Comedogenicity: 1

When it comes to sunscreen agents, Zinc Oxide is pretty much in a league of its own. It's a physical (or inorganic) sunscreen that has a lot in common with fellow inorganic sunscreen Titanium Dioxide (TiO2) but a couple of things make it superior even to TiO2.

If physical sunscreens don't tell you anything, go ahead and read about the basics here. Most of what we wrote about Titanium Dioxide is also true for Zinc Oxide so we will focus here on the differences. 

A white powdery thing that's the major component of glass and sand. In cosmetics, it’s often in products that are supposed to keep your skin matte as it has great oil-absorbing abilities. It’s also used as a helper ingredient to thicken up products or suspend insoluble particles. 

Officially, CosIng (the official EU ingredient database) lists Aluminum Hydroxide 's functions as opacifying (making the product white and non-transparent), as well as emollient and skin protectant.

However, with a little bit of digging, it turns out Aluminum Hyroxide often moonlights as a protective coating for UV filter superstar Titanium Dioxide. Specifically, it protects our skin from the harmful effects of nasty Reactive Oxygen Species (free radicals derived from oxygen such as Superoxide and Hydrogen Peroxide) generated when Titanium Dioxide is exposed to UV light. Btw, chlorine in swimming pool water depletes this protective coating, so one more reason to reapply your sunscreen after a dip in the pool on holiday.

What-it-does: emollient, viscosity controlling | Irritancy: 0 | Comedogenicity: 2-3

A common multi-tasker fatty acid. It makes your skin feel nice and smooth (emollient), gives body to cream type products and helps to stabilize water and oil mixes (aka emulsions).

spherical texturizing powder that's used as a texture enhancer and soft focus agent. It's claimed to give silicone type softness to the formula and also works as a (temporary) wrinkle filler. 

A clear, light yellow liquid that is used to coat pigments (such as inorganic sunscreen agents or colorants) in cosmetic products.  The coating helps to stabilize pigments in the formulas and also helps them to spread easily and evenly on the skin. 

Also-called: Form of Retinoids | What-it-does: cell-communicating ingredient | Irritancy: 1-3 | Comedogenicity: 1-3

It's an ester form of vitamin A (retinol + palmitic acid) that belongs to the "retinoid family". The retinoid family is pretty much the royal family of skincare, with the queen being the FDA-approved anti-aging ingredient tretinoin. Retinol is also a very famous member of the family, but it's like Prince William, two steps away from the throne. Retinyl palmitate will be then little Prince George, quite far (3 steps) away from the throne. 

By steps, we mean metabolic steps. Tretinoin, aka retinoic acid, is the active ingredient our skin cells can understand and retinyl palmitate (RP) has to be converted by our metabolic machinery to actually do something. The conversion is a 3 step one and looks like this:

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. 

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.

Also-called: White Willow Bark Extract | What-it-does: soothing, astringent

The extract coming from the bark of the White Willow, a big (25 m/80 ft.) tree that likes to live on riverbanks. It's famous for containing anti-inflammatory natural salicylates (this powder, for example, is standardized to contain 53-65%), a close chemical relative to famous exfoliant salicylic acid.

Thanks to its salicin content, willow bark is often touted as a natural alternative to salicylic acid, though it's quite questionable how effective it is as a chemical exfoliant in the tiny amounts used in cosmetics. Apart from soothing salicin, it also contains flavonoids and phenolic acids that give willow bark tonic, astringent, and antiseptic properties.

Also-called: Aqua | 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: 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.

A little helper ingredient that works as a preservative. It works against bacteria and some species of fungi and yeast. It's often combined with IT-preservative, 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.

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.

You may also want to take a look at...

what‑it‑does sunscreen | colorant
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]
what‑it‑does sunscreen
irritancy, com. 0, 1
A physical/inorganic sunscreen with the broadest spectrum (UVB and UVA II, less good at UVA I) protection available today. It also has good stability and also works as a skin protectant, anti-irritant. Might leave some whitish tint on the skin, though. [more]
what‑it‑does viscosity controlling
A white powdery thing that can mattify the skin and thicken up cosmetic products. [more]
what‑it‑does emollient | moisturizer/humectant | viscosity controlling
Officially, CosIng (the official EU ingredient database) lists Aluminum Hydroxide 's functions as opacifying (making the product white and non-transparent), as well as emollient and skin protectant. However, with a little bit of digging, it turns out Aluminum Hyroxide often moonlights as a protective coating for UV filter superstar Titanium Dioxide. [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 0, 2-3
A common multi-tasker fatty acid that works as an emollient, thickener and emulsion stabilizer. [more]
A spherical texturizing powder that's used as a texture enhancer and soft focus agent. [more]
A clear, light yellow liquid that is used to coat pigments (such as inorganic sunscreen agents or colorants) in cosmetic products.  [more]
what‑it‑does cell-communicating ingredient
irritancy, com. 1-3, 1-3
An ester form of vitamin A (retinol + palmitic acid) that is pretty much the least effective member of the retinoid family. Its anti-aging effects are quite questionable as well as its behavior in the presence of UVA light. (Use it at night if possible!) [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 antioxidant
irritancy, com. 0, 2
An oil soluble vitamin C derivative that has mixed data about its effectiveness. [more]
what‑it‑does soothing
White Willow Bark Extract - Famous for containing anti-inflammatory natural salicylates. It also has tonic, astringent, and antiseptic properties. [more]
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 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 preservative | antimicrobial/antibacterial
A little helper ingredient that works as a preservative. It works against bacteria and some species of fungi and yeast. [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 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.