MoroccanOil Moroccanoil Treatment Hair Oil Versus Hask Argan Oil Repairing Hair Oil

Two clinical studies in postmenopausal women found that applying argan oil for 60 days significantly improved skin elasticity and moisturization (reduced transepidermal water loss and increased epidermal water content).

Since it is high in oleic and linoleic acid, this ingredient may not be fungal acne safe. Both of these fall in the C11-C24 range that Malassezia yeast can metabolize.

On concentrations, neither the EU nor the FDA sets a hard number. The EU allows it with purity limits on leftover manufacturing residues and the FDA allows it in externally applied cosmetics at levels consistent with batch-certified good manufacturing practice.

Industry reports around 0.5% concentration usage in leave-on products, but most products use far less because it's a pretty strong dye.

The one rule that both regions share is that it isn't allowed anywhere it would touch mucous membranes (so no lipstick or eye products).

That restriction comes from an unresolved 2005 EU data request on how much of the dye penetrates skin and breaks down there, and not from any reported consumer harm.

Allergy risk is low and a guinea pig study ranked it a much weaker sensitizer than common hair-dye chemicals. But the same study found animals sensitized to paraphenylenediamine sometimes cross-reacted to it, so it's worth flagging for a patch test if you have a known permanant-hair-dye allergy.