Yes, studies have shown that red light therapy (using red light helmets) can improve blood flow in the scalp to promote hair growth. Some scientists believe that, in particular, male pattern hair loss is caused by impaired blood flow in the scalp. As a result, improving blood flow may help ensure that enough nutrients reach the hair follicles, encouraging new hair growth. Based on a study from 2021, low-level 650 nm red light promoted the proliferation of human hair follicles in the experimental cultured-tissue model.