Citronella (lemongrass) essential oil is used in traditional medicine for many years to calm headaches and migraines, treat nausea, eliminate fatigue and relieve stomach aches. Some of its benefits: -Its fresh woody aroma revitalizes, tones and acts as an effective insect repellent. -It repels effectively annoying insects, especially mosquitoes during the summer months. -It is also used to repel lice and prevent them from appearing on the scalp.