Why do people sometimes lose their hair when they take chemotherapy? Does it grow back? Chemotherapy stops most cells from dividing and growing, including hair cells. While you are going through chemotherapy, the cells that make your hair and keep your hair attached to your head cannot do their job. Once you stop receiving chemotherapy, you hair will slowly begin to grow back, but it may be a different color or have a different feeling than before your treatment. Answered by Dr. Regina Jakacki, pediatric oncologist, Children's Hospital of Pittsburgh July, 2007