Hexanal is an organic compound that occurs naturally in many plants, from elderflowers to apples. It is largely responsible for the bright green scent you smell after mowing the lawn and can even lend grassy notes to whiskey, imparted by the oak barrels in which it has been aged. It is also found in bergamot essential oil, which has been found to have many health benefits.
A 2017 pilot study found that women in the waiting room of a mental health treatment center who inhaled bergamot oil for only 15 minutes experienced improved positive feelings. This suggests that bergamot oil aromatherapy could be an effective adjunct treatment to improve one's mental health and well‐being. 1
A 2006 study involving 52 patients with hypertension suggests that bergamot oil, in combination with other essential oils, can be used to help reduce psychological stress responses blood pressure levels. 1