Are essential oils safe during pregnancy?

What does the evidence say about essential oils during pregnancy?

1. Some essential oils are considered safe in specific uses, like peppermint oil for irritable bowel symptoms, while others are toxic if swallowed and need a clinician's guidance before use. 1
2. Swallowing essential oils can be harmful, and applying concentrated oils directly to skin can cause a rash, so neither is something to try casually during pregnancy. 1
3. Essential oils fall under the same rules as herbal supplements: they don't need safety review before hitting shelves, so strength and purity can vary quite a bit from bottle to bottle. 2
4. Peppermint oil is a good example of how evidence varies by oil: culinary and short-term therapeutic use has real research behind it, while most other essential oils, including in pregnancy, have much thinner data. 3

Is essential oils safe in each trimester?

• First trimester. A few oils, clary sage, rosemary, cinnamon leaf, pennyroyal, sage, and wintergreen, are best skipped in the first trimester. Ginger and citrus oils in a diffuser are usually fine.
• Second trimester. The same avoid list still applies. Diluted topical use now and then may be okay with your provider's input, but skip continuous or highly concentrated application.
• Third trimester. Clary sage is sometimes used late in labor, but only by trained providers in a supervised setting. That's a different situation entirely from using it on your own in the third trimester.