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Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Photostabilizers help stabilize UV-filters and prevents them from degrading quickly.

Though Caprylyl Glycol is an alcohol derived from fatty acids, it is not the kind that can dry out skin.

This ingredient is also used as a preservative to extend the life of products. It has slight antimicrobial properties.

Hectorite is a rare, white clay mineral.

As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.

Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.

Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.

In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.

This ingredient is organic, colorless, odorless, and non-toxic.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

On the other hand, emulsifiers prevent ingredients (such as oil and water) from separating.

Some foods that contain glyceryl glucoside include sake, miso, and wines.

What makes hyaluronic acid so hydrating? It has the capacity to bind or hold large amounts of water.

Fun fact: It is already naturally found in our bodies, such as the fluids of our eyes and our joints.

Studies find this ingredient to have anti-inflammatory and anti-microbial properties. This can help speed up wound-healing.

Hyaluronic acid can be irritating if the molecule has a low-molecular weight, or if the molecules are small.

One study found low-molecular weight hyaluronic acid to be pro-inflammatory, meaning some people may experience irritation. This is because our bodies use hyaluronic acid in the wound-healing process to signal to our bodies, via irritation, that something needs healing.

The same study found high-molecular weight hyaluronic acid to be anti-inflammatory.

These are some other common types of Hyaluronic Acid:

You might recognize Magnesium Sulfate as epsom salt, or the bath salt used to help relieve muscle aches.

One study shows magnesium deficiency may lead to inflammation of the skin. Applying magnesium topically may help reduce inflammation.

Emulsifiers help stabilize a product. It does this by preventing certain ingredients from separating.

Methyl Trimethicone does not get absorbed into the skin.

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Sodium Hyaluronate is naturally occurring in our bodies and is mostly found in eye fluid and joints.

These are some other common types of Hyaluronic Acid:

Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.

You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.

There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.

Triethoxycaprylylsilane is often used to coat mineral sunscreens ingredients to help give a better feel. It also helps reduce oxidative stress in sunscreens.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Stay hydrated!

Another great benefit? This ingredient is highly photostable so it won't degrade easily under sunlight.

A common myth is that mineral UV filters are widely believed to primarily reflect UV light.

However, modern research shows titanium dioxide absorbs UV radiation like chemical filters (~95% absorption & 5% reflection).

Zinc oxide has great skin soothing properties so you'll likely find this in sunscreens formulated for sensitive skin or babies/children. It is unlikely to cause "eye sting" like other sunscreen ingredients.
Regulatory agencies consider zinc oxide to be non-toxic and safe. It has also been shown to not penetrate the skin.

Unfortunately, this ingredient does leave a visible white cast. This is why mineral sunscreens are often less cosmetically elegant than chemical or hybrid ones.

In cosmetics, zinc oxide can be found in both non-nano and nano-sized forms. The nano version is used to reduce white cast and improve the texture of sunscreen formulas.

There are ongoing concerns surrounding nano-zinc oxide's impact on marine ecosystems and whether it can be absorbed into skin.

Regarding marine ecosystems and coral reefs, there is no conclusive evidence that any form of zinc oxide (or any other sunscreen ingredients) will cause harm. The science is still developing but many consumers are keeping a close eye on this issue.

Please note, many destinations have reef-safety sunscreen rules. For instance, the U.S. Virgin Islands advises all visitors to use non-nano mineral sunscreens.

There has also been some stir about whether micronized or nano zinc oxide has potential photoxicity and absorption through the skin/lungs.

An in-vitro (done in a test tube or petri dish) study demonstrated micronized zinc oxide to have potential phototoxicity. There's no need to fret; the EU Commission's Scientific Committee on Consumer Safety has stated, "The relevance of these findings needs to be clarified by appropriate investigations in vivo." Or in other words, further studies done on living organisms are needed to prove this.

Current research shows zinc oxide nanoparticles do not penetrate intact or sunburned skin. They either remain on the surface or in the outermost layer of dead skin (stratum corneum).

Zinc oxide is one of only two classified mineral UV filters with titanium dioxide being the other one.

Fun fact: Zinc has been used throughout history as an ingredient in paint and medicine. An Indian text from 500BC is believed to list zinc oxide as a salve for open wound. The Ancient Greek physician Dioscorides has also mentioned the use of zinc as an ointment in 1AD.