Cosmetic hair care products are often implicated by the user or the clinician in cases of hair loss. Yet, these products are used ad lib, in a wide variety of home conditions and on a wide variety of hair types, by millions of consumers every day with no adverse effects. Based on this extensive data set, the absence of literature reports, and a detailed understanding of the mode of action of cosmetic hair care products, we can conclude that they do not cause hair loss. Clinicians investigating cases of hair loss must fully appreciate the hair cycle, the length of time a single fibre may be present on the head, and its biological and cosmetic history in order to understand the causes of hair loss and make the correct diagnosis. With a better understanding of the cosmetic practices used by everyday consumers, the clinician will be in a strong position to help patients re-grow their hair and guide them through a high quality hair care regime.