Have you have bloodwork done, lunaticfringe? My grown daughter (who has extremely thick, lush hair) was losing her hair. Doctor did bloodwork & found out that my daughter had a severe vitamin D deficiency. Doc put her on a prescription amount of vit D, told her to sit in the sun for 10 mins every day (she had always avoided the sun) & within 3 weeks my daughter's hair wasn't falling out anymore. So weird, but entirely true.