Rosemary oil is generally considered safe when used topically or in aromatherapy. However, some individuals may experience headaches or allergic reactions when exposed to the scent of rosemary oil or when it comes into contact with their skin.

Headaches caused by rosemary oil are relatively rare but can occur in individuals who are sensitive or allergic to the oil. The strong aroma of rosemary oil can trigger headaches in some people, especially if they have a pre-existing sensitivity to strong scents.

To avoid potential headaches or allergic reactions, it is recommended to dilute rosemary oil with a carrier oil (such as coconut or jojoba oil) before applying it to the skin. This can help reduce the concentration and potential irritation of the oil.

If you experience persistent headaches or any adverse reactions after using rosemary oil, it is advisable to discontinue use and consult with a healthcare professional for further guidance.