“According to Medline Plus,5 the diluted form of eucalyptus oil is taken orally for pain and inflammation of respiratory tract mucous membranes, coughs, asthma, bronchitis, sinus pain and inflammation, and respiratory infections. It is also used as an antiseptic, insect repellent, and treatment option for wounds, burns, and ulcer.
For healing mucus membranes (such as to safely and effectively treat allergies and asthma), you can apply a drop of eucalyptus oil on an organic cotton ball and sniff it several times a day. I also recommend adding a few drops to water or a nebulizer as steam therapy, or you can use a few drops in your bath water.” Mercola.com
Yet, eucalyptus oil can be used for hair! The oil activates or stimulates the scalp while creating a natural oil coating on each strand. This protects the hair from splitting and engages growth from scalp stimulation.
According to the American Athletic Institute (a blog I might say) http://www.americanathleticinstitute.org/natural-home-remedies/101-tips-on-how-to-make-your-hair-grow-quicker.php , details other healthy tactics for growth.