There have been many studies on the use of essential oils for pain, and a wide range of essential oils has been studied in this regard. Though the quality of the studies is not necessarily always good, this must be weighed against the fact that most of the studies report positive results. Evidence-based medicine should not be interpreted to mean that anything but randomised double-blind placebo-controlled clinical trials should be disregarded. This is not only unrealistic, but also unworkable when dealing with real life scenarios. Lesser quality evidence should be considered if the direction in which it points is unequivocal, unless larger and better trials contradict this evidence.
Sarmento-Neto et al. (2015) carried out a review of studies of antinociceptive activity of essential oils. In the studies reviewed the antinociceptive activities of 31 essential oils were demonstrated in rodents and the mechanism of action identified (peripheral or central). The lack of clinical studies was attributed to the need for more extensive pre-clinical investigations on the toxicity and safety of the essential oils. Among the better known and more commonly available Old World essential oils demonstarting antinociceptive activity were: clove (Eugenia caryophyllata), common basil (Ocimum basilicum), eucalyptus (Corymbia citriodora / syn. Eucalyptus citriodora), German chamomile (Matricaria recutita), ginger (Zingiber officinale), Indian valerian (Valeriana jatamansi / syn. Valeriana wallichii), lemon (Citrus limon), lemongrass (Cymbopogon spp.), and summer savory (Satureja hortensis). Mechanisms of action identified were mainly peripheral although some essential oils acted centrally at least in part (common basil, ginger, lemon). Oils of clove, common basil, ginger and lemon were found to have opioid agonist activity.
A paper by Barão Paixão et al. (2021) presented a systematic review of the published research evaluating topical and inhaled essential oils in rheumatic diseases. Three rheumatic diseases were included in the reviewed studies: fibromyalgia, osteoarthritis, and rheumatoid arthritis. Thirteen studies fulfilled the inclusion criteria, of which 12 found the tested essential oils to be effective against pain. Massage was the most used method of essential oil application, with two studies using inhalation. Lavender essential oil was the most used followed by rosemary, eucalyptus and ginger and peppermint.
[1] Sarmento-Neto JF, do Nascimento LG, Felipe CF, de Sousa DP. Analgesic Potential of Essential Oils. Molecules. 2015;21(1):E20. Published 2015 Dec 23. doi:10.3390/molecules21010020
[2] Barão Paixão VL, Freire de Carvalho J. Essential oil therapy in rheumatic diseases: A systematic review. Complement Ther Clin Pract. 2021;43:101391. doi:10.1016/j.ctcp.2021.101391
Robert Hale, 27 July 2022.
Old World Medicinal Plants 