Jane Iredale PurePressed Base Mineral Foundation Versus Jane Iredale Hydropure Tinted Serum with Hyaluronic Acid & CoQ10

Generally, it is used to hold water and soften skin in a formula. Algae are rich in polysaccharides, pigments, and amino-acids that act as humectants, emollients, and skin-conditioning agents.

It isn't on standard cosmetic-patch test panels and "seaweed dermatitis" is actually an acute irritant reaction to algal toxins in seawater and not the cosmetic ingredient.

You'll see algae listed as a 5/5 on a lot of pore-clogging charts and that number doesn't come from anywhere; it's not in the original rabbit-ear studies that most comedogenic ratings trace back to.

The reasoning behind the reputation is that seaweed is high in iodine and iodine can trigger acne-like breakouts when eaten. This traces back to a 1976 letter in Archives of Dermatology describing two women whose breakouts cleared after they stopped taking high-dose kelp supplements orally.

And the reaction of these two women wasn't clogged pores at all: it was an iodine-triggered pustular rash. Later research found normal dietary iodine doesn't meaningfully affect acne either and nobody has shown topical algae delivers enough iodine to matter.

What we do have is dozens of brown and red algae ingredients found to be non-irritating and non-sensitizing, and a handful of studies that found algae compounds may actually help acne.

However, plenty of people do report breaking out from algae-containing products. Skin is individual and it's worth avoiding if yours has reacted to algae before.

This ingredient is often coated with metal oxides like titanium dioxide. Trace amounts of heavy metals may be found in mica, but these metals are not harmful in our personal products.

Mica has been used since prehistoric times throughout the world. Ancient Egyptian, Indian, Greek, Roman, Aztec, and Chinese civilizations have used mica.