How do drugs affect the hair follicles and therefore hair loss?
This is such a broad question that it’s hard to give a satisfactory answer. Drugs like hormone pills, contraceptives, even antibiotics can cause temporary hair loss in some individuals. But the drugs used in chemotherapy for cancer can have dramatic effects. These drugs shut down the growing stage (anagen) of the hair cycle. Since ninety percent of the hair follicles are in this stage at one time, ninety percent of the hair can be lost and lost quickly. This is called anagen effluvium. The hair loss is temporary. The hair will usually grow back after the chemotherapy stops.
