Q: Dear Dr. Power: Are there any essential oils that are harmful to use if you have hypertension that is being treated with medication? I was told by someone that I should not use cypress oil and others have told me that it is all right.
A: According to the widely used professional reference, Essential Oil Safety - A Guide for Healthcare Professionals, by Robert Tisserand and Tony Balacs, it is very unlikely that any essential oils used externally in reasonable amounts could increase hypertension. In general, however, most aromatherapists recommend that persons with hypertension avoid the following oils: hyssop, rosemary, sage and thyme. Some recommend avoiding cypress as well since it is mildly anti-diuretic.
Since peace of mind is so important, I think you should stick with essential oils with which you feel absolutely comfortable. You may wish to visit our web site and read a bit more about the properties of various essential oils.