The Ordinary Serum Foundation Versus Mac Cosmetics Studio Fix Powder Plus Foundation

According to manufacturers, this ingredient is an emollient and humectant. This means it helps hydrate the skin.

In medicine, this ingredient is used to help relieve heartburn and help heal ulcers.

There is currently no credible scientific evidence linking aluminum hydroxide in cosmetics to increased cancer risk.

Major health organizations allow the use of aluminum hydroxide in personal care products and have not flagged it as a carcinogenic risk at typical usage levels.

Due to its structure as flat, plate-like crystals that stack like tiles, it feels silky and sticks to skin well. This also makes it very chemically stable and insoluble under normal skin conditions (this just means it sits on top of skin rather than going into it).

It has an interesting quirk: it slowly goes gray in sunlight and the graying is partly reversible in the dark.

At this time, there's no legal cap on how much a brand can use. Both the FDA and the EU permit it without restriction so real-world concentration levels come down to formulation:

Allergy risk is low as well since it's insoluble and doesn't release free metal ions into skin. True allergic contact dermatitis to it is rare enough that there's very little published cases.

However, mineral makeup users do report itching or stinging. The leading explanation for this is irritation from those stiff platelet crystals rubbing on skin (also more likely with heavy, high-percentage loose mineral powders) rather than an immune reaction.

This ingredient shows up on a lot of "pore-clogging" lists but there's no real evidence behind that. It doesn't even have a comedogenic rating from an actual study; the numbers you'll find online come from blogs citing other blogs.

Some people still find it breaks them out. So if that's you, definitely trust your skin.

Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.