Mint Family (Lamiaceae)
Lavender is one of the most recognised and widely used herbs in the world. Lavender has long been used to scent laundry, and its name comes from the French word ‘lavare’, which means to wash. The fragrance of lavender immediately has a relaxing effect, revealing some of its medicinal qualities. Like many aromatic plants, it also has strong antimicrobial properties.
Anxiety, relaxation, sleep
Various studies have shown that the scent of lavender improves mood (Ogata et al., 2020), lowers blood pressure and heart rate (Sayorwan et al., 2012), strengthens theta and alpha brain activity - the kind seen during sleep and meditation (Sayorwan et al., 2012), and decreases levels of the stress hormone cortisol (Hosseini et al., 2016).
A systematic review of studies of the effects of lavender use on anxiety found 65 randomised control trials (RCTs) and 25 non-randomised studies (NRSs) for qualitative synthesis and 37 RCTs for quantitative synthesis (Donelli et al., 2019). The qualitative synthesis found that 54 RCTs and 17 NRSs found a statistically significant benefit of lavender use for anxiety. Similarly, the quantitative analysis revealed that lavender inhalation could significantly reduce anxiety levels, although there was not a significant effect in reducing systolic blood pressure, the force with which the heart pumps blood throughout the body. However, the limitations of this systematic review stem from risks of bias in many of the RCTs studied that lacked double blinding, as well as from the variation in study designs, especially with regard to studies involving inhalation (Donelli et al., 2019).
Lavender is considered to help relieve the kind of depression associated with fixation on a specific traumatic event (De la Foret, 2017). It has also been found to improve mood of women at high risk for postpartum depression. In one study, 105 pregnant women at 35–37 weeks of pregnancy were randomly assigned to three groups - intervention, placebo, and control (Kianpour et al., 2015). The intervention group protocol was 7 drops of lavender oil and 1 cc rose water at the concentration of 100%, and the placebo group protocol was 7 drops of odourless sesame seed oil, with 1 cc of musk willow sweat at the concentration of 100% by dropper on a special cloth. Each participant put the cloths on their mouths and took 10 deep breaths before sleeping, and placed the cloths next to their pillows. This lasted from the 38th week of pregnancy until 6 weeks after childbirth. The results showed the mean depression score in the intervention group was significantly lower than in the placebo and control groups at two and six weeks after delivery (Kianpour et al., 2015).
A randomised control study of 108 children was done to assess effectiveness of lavender inhalation on pain level and vital signs of children with burns (Esra et al., 2021). Children were in three groups: receiving lavender oil inhalation 15 minutes before dressing of burn area; 60 minutes before dressing; and a control group receiving base oil inhalation 15 minutes before dressing. In post-dressing measurements, respiration, heart rate, mean arterial blood pressure and pain levels were all significantly lower in the lavender inhalation groups after one minute and after 30 minutes compared to the control group (Esra et al., 2021).
Another study explored the effect of topical lavender essential oil application on intravenous catheterisation via a randomised clinical trial with 66 elective surgery patients (Jometondoki et al., 2019). The intervention group patients were given three puffs of lavender essential oil on the insertion sites, and the control group patients were given three puffs of distilled water. Pain severity scores were significantly less immediately, five minutes, and 10 minutes after catheterisation compared to the scores of the control group patients (Jometondoki et al., 2019).
In a clinical trial of 80 nursing and midwifery students experiencing menstrual pain, students were randomly assigned lavender oil or placebo oil to apply on the first two days of menstruation for two cycles (Bakhtshirin et al., 2015). Pain was assessed 30 minutes after application. The results showed a significant decrease in the visual analog scale (VAS) pain assessment score compared to the placebo massage. While there was also a significant difference between scores before and after the placebo massage, the effect of lavender massage on pain was higher than that of the placebo massage (Bakhtshirin et al., 2015).
Lavender has traditionally been used to help with sleep, and research has also demonstrated this effect. In one randomised controlled trial of 68 palliative care patients, lavender oil applied to patients in an experimental group, and their sleep quality and that of patients in a control group, was assessed in the morning (Yildirim et al., 2020). The experimental group patients had deeper sleep on the second day; found it easier to fall asleep and sleep again after awakening; had reduced awakening frequency on the first two days; and had better sleep quality (Yildirim et al., 2020).
Migraines - Pain & Prevention
A randomised clinical trial of patients with diagnosed migraines were assigned to intervention and control groups to assess treatment potential of lavender essential oil (Sasannejad et al., 2012). The intervention group patients inhaled lavender essential oil for 15 minutes and the control group patients inhaled liquid paraffin for 15 minutes; all patients recorded severity and symptoms in 30-minute intervals over two hours. There was a statistically significant difference in the reduction of headache severity between the two groups (Sasannejad et al., 2012).
To assess the potential of lavender in preventing migraines, a double-blind, placebo-controlled study was done over three months using a Persian variety of lavender, Lavandula stoechas (Rafie et al., 2016). There was a statistically significant reduction in the Migraine Disability Assessment Scores in the treatment group compared to the baseline scores and compared to the control group after three months (Rafie et al., 2016). This study used a different variety of lavender than has been used in most studies, but as the extract was standardised to have linalyl acetate (0.6%) and linalool (0.4%), it is possible that L. angustifolia extracts with these compounds may have similar effects.
Two studies found that lavender essential oil applied topically to women recovering from an episiotomy (a cut made to facilitate childbirth) was as effective as a standard antiseptic in reducing pain, preventing complications and and reducing redness (Vakilian et al., 2011).
According to herbalist Maude Grieve, lavender was used to treat wounds during World War 1, and in 1910 French chemist Rene Maurice Gattefosse used lavender essential oil to treat his own burns from a laboratory explosion (De la Foret, 2017).
A broad systematic review of studies on the wound healing effects of lavender essential oil found 20 studies based on human clinical trials, animal trials, in vitro studies, and previous reviews (Samuelson et al., 2020). Taken together, these studies supported faster wound healing, greater expression of collagen, and enhanced activity of proteins in the tissue remodelling process. In one such animal model study, topical treatment of wounds with 1% lavender oil solution resulted in a significant decrease in wound size compared to the wounds of control animals at 4, 6, 8, and 10 days after wounding (Mori et al., 2016).
Like rosemary, lavender’s aroma and warmth helps with cold or stagnant digestion, and for calming cramps, spasms, or nervous stomachs (De la Foret, 2017).