The effect of lavender on mood disorders associated with the use of combined oral contraceptives (COCs): a triple-blinded randomized controlled trial

Background The use of contraceptive methods is influenced by their effectiveness, availability, and minimal side effects. OCPs are one of the most effective and widely used methods of pregnancy prevention worldwide. This method not only prevents pregnancy but also helps prevent and treat other diseases. One of the main reasons for discontinuing this method is the emotional disturbances associated with its use. Lavender is an evergreen, fragrant plant that has gained significant attention for its anti-anxiety effects. This study was conducted to investigate the effect of lavender essential oil capsules on mood disorders during the use of COCs. Methods This triple-blinded clinical trial was conducted on 60 married women (aged 15-49 years old) who were consumers of COCs, referring to 26 health centers in Tabriz, Iran. The participants were randomly assigned to either the intervention (consuming one gelatin capsule containing 80 mg LEO daily) or control (consuming one placebo capsule daily) group. The intervention continued for 56 days. Scores for positive and negative were determined using the Positive and Negative Affect Schedule (PANAS) questionnaire; and for stress, depression, and anxiety were measured using the DASS-21 questionnaire on day's 28th and 56th post-intervention. Data analysis was conducted using the t-test and ANOVA with repeated measures, and a p-value of < 0.05 was considered significant for all analyses. Results A statistically significant difference was observed in mood disorders, stress, and depression between women receiving LEO or placebo. The consumption of LEO increased the positive mood on day 28 [MD (95% CI): 4.5 (2.1 to 7.0), p = 0.001] and day 56 [5.9 (3.4 to 8.3), p < 0.001] while decreased the negative mood on day 28 [MD (95% CI): -3.5 (-5.3 to -1.3), p < 0.001] and day 56 [-4.3 (-6.3 to -2.2), p < 0.001], stress on day 28 [MD (95% CI): -4.9 (-7.1 to -2.8), p = 0.001] and day 56 [-5.3 (-7.6 to -3.1), p < 0. 001], and depression on day 28 [MD (95% CI): -3.0 (-4.9 to 1.1), p = 0.003] and day 56 [-3.1 (-5.0 to 1.2), p = 0.002]. There was no statistically significant difference between the two groups in terms of anxiety. Conclusions The consumption of LEO with COCs improved mood disorders and reduced stress and depression. The use of hormonal contraceptives and mood changes should be considered by providers. Therefore, regarding the possibility of mood changes, it is expected that appropriate counseling and education will be provided to women who consume COC., providing appropriate solutions, including the simultaneous use of LEO.