Xtensions & Hairstyles Argan Oil leave in hair treatment. Moroccan Argan oil is a rich moisturising and nourishing treatment enriched with Vitamin E. This treatment will leave your hair soft, smooth and with a rich healthy natural sheen. Simply apply a small amount to damp or dry hair and style. This treatment will also act as a protector against heated appliances (30ml). We cannot express enough, this is a must have for your hair extensions.