A small randomized, double-blind, placebo-controlled study was performed on 40 female patients experiencing fatigue more than 5 months after a COVID-19 infection. The participants inhaled a commercial mixture of the essential oils of thyme, orange peel, clove bud, and frankincense or placebo twice daily for two weeks. The total score determined by the Multidimensional Fatigue Symptom Inventory, the scores of its ten subdomains, and the Patient Health Questionnaire-9 were evaluated. After two weeks, participants in the verum group showed significantly lower fatigue scores (p = 0.020) and according to the resulting subscales also vigor as well as global, behavioral, general, and mental fatigue were improved by the blend.
Source: Hawkins J, Hires C, Keenan L, Dunne E. Aromatherapy blend of thyme, orange, clove bud, and frankincense boosts energy levels in post-COVID-19 female patients: A randomized, double-blinded, placebo-controlled clinical trial. Complement Ther Med 2022;67:102823. Doi: 10.1016/j.ctim.2022.102823.