Yes. Lack of sleep has a direct impact on the quality and fullness of a man's hair – leading to breakage and hair loss.
Hair growth begins in the hair follicles, and for them to function properly they need nutrients, vitamins, and minerals from blood flow. The increase in blood flow when we’re sleeping means more nutrients, resulting in stronger hair and improved growth.
Lack of sleep can also lead to more stress and the release of the stress hormone cortisol. Another cause of hair loss!