Absence of effects of dimethicone- and non-dimethicone-containing shampoos on daily hair loss rates

Abstract

To understand why consumers associate hair fall to the use of shampoo, a clinical study was conducted to examine daily hair loss rates in a large population of 404 healthy Thai females using either a dimethiconeor non-dimethicone-containing cosmetic shampoo for a period of six weeks. In addition, perceptual information was obtained on hair fall, hair health, and causes of hair shedding and hair loss. While published estimates of average daily hair loss rates range from 34.8 to 180 hairs (2-7), this study found mean hair loss rates ranging from 28 to 35 per day in a population of 404 healthy Thai females over a period of six weeks. These daily hair loss rates are consistent with reported findings in the normal population (2-3,8). There were no significant differences in the total, telogen, anagen, and broken hair loss rates between the three different shampoo groups. As expected, significantly higher hair loss rates were noted on shampoo versus non-shampoo days. No differences were noted in the perception of hair fall in subjects using the three different shampoos. In this study, we determined why consumers associate hair fall with the use of shampoo. While subjects perceived hair fall as a natural process in hair regrowth and therefore unrelated to hair thinning or balding, they attributed any increased hair fall from grooming to the use of unsuitable shampoos, more so than to the grooming processes of combing/brushing or to chemical modification. Other factors known to contribute to abnormal hair loss were not perceived by the subjects as likely causes of hair fall.