Lavender essential oil has a calming scent which makes it an excellent tonic for the nerves and anxiety issues. Therefore, it can also be helpful in treating migraines, headaches, depression, nervous tension and emotional stress. The refreshing aroma removes nervous exhaustion and restlessness while also increasing mental activity. It has a well-researched impact on the autonomic nervous system, which is why it is frequently used as a treatment for insomnia and also as a way to regulate heart-rate variability. One study showed that people taking tests showed a significant decrease in mental stress and anxiety, as well as increased cognitive function when they inhaled lavender oil and rosemary oil before taking the exam!