title: 'Bad hair days', scalp sebum excretion and the menstrual cycle.
abstract: BACKGROUND
  Many women complain that their hair is periodically unmanageable, popularly known as 'bad hair days' (BHDs). At an anecdotal level BHDs are more common around the time of menstruation and, in view of previous studies reporting menstrual variation in sebum excretion, the authors hypothesised that changes in scalp sebum levels during the menstrual cycle might contribute to perceive differences in hair quality.
  
  
  OBJECTIVE
  To test whether there is a relationship between BHDs, the menstrual cycle and scalp sebum excretion.
  
  
  METHODS
  Thirteen women were studied through three menstrual cycles. Sebum levels on the scalp and forehead were measured twice weekly using a Sebumeter and each subject kept a record of hair quality and hair washing practice.
  
  
  RESULTS
  BHDs occurred throughout the menstrual cycle but were more common during menstruation. There was no discernible variation in sebum levels on the scalp or forehead during the menstrual cycle and there was no correlation between individual mean skin sebum levels and the frequency of BHDs. However, BHDs were more common in those women who washed their hair infrequently, although the association between the frequency of hair washing and BHDs just failed to reach statistical significance (p = 0.06).
  
  
  CONCLUSIONS
  BHDs are more common during menstruation and in women who wash their hair infrequently. This may relate to a build-up of sebum on the hair but menstrual variations in the frequency of BHDs are unrelated to sebum levels.
authors.affiliation: Department of Dermatology, Royal Hallamshire Hospital, Sheffield UK.
authors.forename: M Pattie
authors.initials: MP
authors.lastname: Birch
authors.forename: Andrew
authors.initials: A
authors.lastname: Messenger