Why do you need to dilute some essential oils when used topically?

Essential oils are much more concentrated than the plants they come from, which is why some of them need to be diluted before being applied to the skin. Certain oils are considered gentle and are commonly used neat or with little dilution, such as lavender, myrrh, and frankincense. Others are much stronger or “hotter” on the skin, such as cinnamon and oregano, and may cause irritation if applied directly. Diluting these oils with a carrier oil helps make topical use safer and more comfortable.