While not everyone who undergoes chemotherapy loses their scalp and facial hair, most patients do. The average chemotherapy-induced madarosis rate depends on the type of medication you use. A study conducted on 838 breast cancer survivors who underwent chemotherapy revealed eyebrow loss in 89% of the cases and eyelash loss in 87% [10]. However, this facial hair loss is temporary and will grow back within a few weeks or months after treatment completion.