It really depends on the individual, going two weeks between washing can cause your natural oils to build up. Frequent combing to bring the oil from the scalp to the ends of the hair is recommended. Argan oil is a moisturizing oil, so it is adding to the natural moisture and oil in your hair. If you are going 2 weeks without washing it may be that your scalp is creating enough oils. My suggestion would be to start using it on your ends and as a hair mask before you wash your hair. Good luck!
thank you for the advice, I will try that next time! Have you tried Amal Oils yet?