Rosemary oil might be inhaled or used topically. It’s very concentrated, so you should only use a couple of drops at any given time. The compact bottles in which it’s sold consist of plastic droppers that make it simpler to dispense one droplets. Massage the oil on to dry hair; https://allhealthmarket.com/product/health-and-beauty-2/hair-care/biotin-hair-oils-for-hair-growth-anti-breakage-hair-growth-and-collagen-for-natural-hair-growth-anti-hair-loss/