200 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table I Mean Daily Total, Telogen, Anagen, and Broken Hair Loss Rates During Baseline and Treatment Periods Difference in hair Mean hair Mean hair loss/day loss/day loss/day (treatment to (baseline period) (treatment period) baseline period) Standard Standard Standard No. of error error error Treatment subjects Mean of means Mean of means Mean of means Total hair loss Shampoo I* 129 35.43 1.97 29.35 1.57 - 6.09 1.12 Shampoo II** 138 29.93 1.86 27.60 1.77 - 2.33 0.98 Shampoo TIT*** 137 31.62 1.96 27.77 1.65 - 3.85 1.21 IT. Telogen hair loss Shampoo I* 129 30.27 1.74 25.55 1.39 -4.72 0.99 Shampoo II** 138 24.90 1.64 23.35 1.54 - 1.56 0.81 Shampoo TIT*** 137 27.07 1.76 24.14 1.44 - 2.93 1.18 III. Anagen hair loss IV. Shampoo I* 129 0.06 0.02 0.02 0.01 -0.04 0.02 Shampoo II** 138 0.06 0.02 0.09 0.07 + 0.03 0.07 Shampoo III*** 137 0.05 0.02 0.01 0.002 -0.05 0.02 Broken hair loss Shampoo I* 129 5.10 0.60 3.77 0.44 - 1.32 0.35 Shampoo II** 138 4.96 0.53 4.16 0.58 - 0.80 0.49 Shampoo III*** 137 4.60 0.50 3.62 0.42 -0.88 0.34 * Shampoo I is a dimethicone-containing 2-in-1 shampoo. **Shampoo II is a non-dimethicone-containing shampoo. ***Shampoo III is a dimethicone-containing shampoo. Information obtained on shampoo frequencies and product consumption from the hair collection envelopes and product use diaries indicated no significant differences in the mean number of uses of test product over the four-week treatment period for the three treatment groups (Table III). However, significantly less dimethicone-containing 2-in-1 shampoo was consumed during the study in comparison to the non-dimethicone- containing shampoo and the dimethicone-containing shampoo (Table lll). Since the test products were distributed in identical packages to maintain product blindness, product characteristics, particularly product thickness, may have accounted for the decreased consumption of dimethicone-containing 2-in-1 shampoo versus the other shampoos. The dimethicone-containing 2-in-1 shampoo is a more viscous product, and this may have provided better control in dispensing. Consistent with the clinical findings of the absence of effects of shampoos on daily hair loss rates, no significant differences were noted in the subjects' perceptions of the severity of hair fall from the baseline and posttreatment periods with the three different shampoos. However, subjects using the dimethicone-containing 2-in-1 shampoo per- ceived that they had significantly healthier hair than subjects using the second dime- thicone-containing shampoo, and that they had more controlled and less flyaway hair than subjects using the non-dimethicone-containing shampoo (Table IV).

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