Chemical/straightening and other hair product usage during childhood, adolescence, and adulthood among African-American women: potential implications for health.

Few studies have characterized life course hair product usage beyond ever/never. We investigated hair product use from childhood to adulthood, usage patterns in adulthood, and socioeconomic status (SES) correlates among African-American (AA) women. Using self-reported data from 1555 AA women enrolled in the Study of Environment, Lifestyle, and Fibroids (2010-2018), we estimated the usage frequency of chemical relaxer/straightener (≥twice/year, once/year, and rarely/never) and leave-in/leave-on conditioner (≥once/week, 1-3 times/month, and rarely/never) during childhood, adolescence, and adulthood. Latent class analysis was used to identify patterns of adulthood usage of multiple hair products. SES was compared across latent classes. With a mean age of 33 ± 3.4 years, most women reported ever using chemical relaxers/straighteners (89%), and use ≥twice/year increased from childhood (9%) to adolescence (73%) but decreased in adulthood (29%). Leave-in/leave-on conditioner use followed the same pattern. Each of three identified latent classes reported frequent styling product use and infrequent relaxer/straightener use. Class One was unlikely to use any other products, Class Two moderately used shampoo and conditioner, and Class Three frequently used multiple product types (e.g., moisturizers and conditioners). Participants in the latter two classes reported higher SES. Ever/never characterization may miss important and distinctive patterns of hair product use, which may vary by SES.