Run Your Fingers Through Thicker, Fuller Hair!Poor circulation is a major cause of hair loss. This expert formula from Dr. Leonard'sr is fortified with L-Arginine to stimulate circulation at the roots. Conditions your scalp while delivering this powerful amino acid and other valuable nutrients directly to the hair follicles. In just 14 days, it stimulates growth up to 67%. And Proboost helps prevent hair loss. Apply twice daily. 4 oz.