While DevaCurl continues to conduct testing to get to the bottom of the issue, we asked Dr. Dominic Burg, chief scientist, biologist, and trichologist for Évolis Professional, to weigh in on the issue. While Dr. Burg says that some products can cause dandruff and dryness, it's unlikely that a styling or shampoo formula would actually change a hair pattern completely. "The curl pattern is mainly defined by the shape of the hair shafts and the angle that they grow out of the head," Dr. Burg says. "Changing the curl of hair is usually only seen after severe trauma to an area of scalp or after chemotherapy. If the hair has become drier, is damaged, or if there is electrostatic repulsion of the hair via surface charging caused by some chemicals, then the individual shafts may not sit well together, changing the quality of the curls rather than the actual pattern."