ABSENCE OF EFFECTS OF DIMETHICONE ON HAIR LOSS 201 Baseline Product Use 60 B 3O • 50 o, 40 E= 20 z :• lO o 1 2 3 4 5 6 7 8 9 1011121314 Days 6o 5O 30 10 0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728 Days -•- D•meth•cone-contmmng 2-in-1 Shampoo • NOnldlmeth•cone-conta•mng Shampoo • D•meth•cone-contammg Shampoo Figure l. Mean daily total hair loss during baseline and product use periods. Perceptual research aimed at understanding why consumers relate hair fall to the use of shampoos indicates that while subjects perceived hair fall as a natural process in hair regrowth (37.1%) and therefore unrelated to hair fall in hair thinning or balding, they associated any increased hair loss during grooming to the use of unsuitable shampoos (39.1%) more so than to the grooming process of combing/brushing itself (27.7%) or to chemical modification, such as perming (14.6%). Other factors known to contribute to abnormal hair loss, such as childbirth (5.7%), medication (4.2%), nutritional deft- Baseline Product Use 6O 6O B 30 •' 50 -- -- • 40 l:_ . be'--- l = 20 z :• lO o 1 2 3 4 5 6 7 8 91011121314 Days 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728 Days -•- Dimethicone-containing 2-in-1 Shampoo ß -E::t- Non-d•methicone-containing Shampoo • Dimeth•cone-containing Shampoo Figure 2. Mean daily telogen hair loss during baseline and product use periods. 50 40 3O 20

202 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Baseline Product Use •4.5 • 4 g 3.5 .J '• 3 _ •2.5: E :• 1.5 0.5 0 1 2 3 4 5 6 7 8 9 1011121314 Days :4.5 •4 3.5 •3 2.5 2 .5 I o.5 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728 Days _•l Dimethlcone-contaimng 2qn-1 Shampoo -e-)- Non-dlmethlcone-conta•mng Shampoo -•- D•methicone-conta•mng Shampoo Figure 3. Mean daily anagen hair loss during baseline and product use periods. ciency (1.2%), hereditary predilection (1.7%), and acute or chronic illness (2.7%) were not perceived as likely causes of hair fall. DISCUSSION The results of this clinical study support a prior premise that dimethicone and non- dimethicone-containing shampoos do not affect daily hair loss rates. In this study, we observed mean hair loss rates ranging from 28 to 35 hairs per day. While published estimates of daily hair loss rates range from 38.4 to 180 hairs (2-7), this study provides Baseline Product Use 20 •16 jo 14 •12 'l- B lO • 8 E • 6 2 0 1 2 3 4 5 6 7 8 9 1011121314 Days 2O 18 •14 :10 8 •6 4 L2 0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728 Days l•_ Dimethlcone-contalnlng 2-1nil Shampoo + NOnldlmethlcone-containlng Shampoo -•- D•methicone-contalning Shampoo Figure 4. Mean daily broken hair loss during baseline and product use periods.