Colibri Skincare Daily SPF 50+ Moisturizer Versus Colibri Skincare Ultra Light SPF 50+

It is approved for up to 10% in the EU and Asia. However, it is pending approval in the US.

Formulators love it for its stability; its ability to filter UV stays practically unchanged even under intense radiation and it can also help boost the photostability of less stable filters like avobenzone.

It's also a great pick for water resistant products because it's insoluble in water and has a good affinity for keratin.

Because it's a big, heavy molecule, the European Scientific Committee has found to to have very low dermal penetration and negative results for allergenicity.

In vitro testing also showed a low absorption rate and clean results on irritation.

Typical use levels are 1-5% with 5% being the maximum in the EU, Japan, and other markets that allow it. However, this ingredient is not approved yet in the US or Canada.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

Ensulizole primarily protects against UVB radiation (~290-320 nm) but offers some minimal UVA protection. You'll see it often paired with UVA filters to ensure broad-spectrum coverage.

Interestingly, it can help boost SPF and stabilize finicky filters when combined with other UVB absorbers.

The FDA has approved this ingredient for OTC sunscreens up to 4% and the EU's Scientific Committee on Consumer Products concluded that up to 8% is allowed in cosmetics.

In practice, you'll most likely see it formulated around 1-4%.

Safety-wise, it is neither irritating nor sensitizing, shows no photoallergenic potential, and in vivo tests show no mutagenic potential.

You might see discussion about the "double-edged sword" effect of this ingredient. This is because lab tests done on cells in a dish (not on humans) showed Ensulizole can create small amounts of unstable molecules called free radicals that can damage DNA when exposed to UV light. It sounds scary but this is just test-tube research. There hasn't been proof that this can happen when used in a sunscreen on skin.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

This ingredient is biodegradable and commonly available in natural/COSMOS-certified grades.

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

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.