2. Do not use essential oils directly on the skin.

These are highly concentrated substances. Some will burn the skin if used without dilution. The only two oils recommended for use on the skin without dilution are lavender and tea-tree; either can be applied to insect bites or blemishes.

3. Generally, do not use essential oils without the guidance of a trained professional if you are pregnant or breastfeeding . These molecules can be transferred over the placenta and into breast milk. While some are safe, some can cause miscarriage, and some can be harmful to the baby if swallowed during nursing.

4. These substances have potent effects on the body. If you are on medication or your doctor has told you to avoid any type of activity, you should see a professional before trying these medicines. Some conditions that warrant special precautions are hypertension or other heart problems, epilepsy, and skin conditions. People with sensitive skins will need to approach aromatherapy with caution.