Bosley Professional Strength BosRevive Leave-In Thickening Treatment for Non Color-Treated HairBosRevive Leave-In Thickening Treatment for Non Color-Treated Hair rejuvenates the scalp while thickening and reconditioning fragile miniaturized hair. Designed to help inhibit the action of DHT, strengthen the hair and provides an anti-aging effect that helps support the growth of younger, stronger healthier hair. Size: 6.8 oz