Gray hair will not grow out black hair after shaving the head. Gray hair is caused by the reduction of melanin granules in the medulla and cortex of the hair or by the air filling.
1. There are abundant blood vessels in the hair papilla to provide sufficient nutrition for the hair papilla and bulb, and melanin granules can be synthesized smoothly. When the formation of melanin granules in the papilla and bulb is impeded, or when nutrients cannot be transported to the hair due to certain factors, the melanin granules in the medulla and cortex of the hair will decrease or disappear, and gray hair will appear.
2. The cause may be related to mental factors, nutritional factors, genetic factors, etc., so simply shaving the head can not make gray hair black.
Gray hair after shaving will not grow black hair, need to be perfected by the doctor to check the cause of the disease, give targeted treatment or standardized treatment.