The most common use for rosemary is cooking the herb to spice dishes such as spaghetti, or lasagna. Rosemary can also have medicinal purposes when used in herb form. Rosemary oil can be used for aromatherapy and baths. There are benefits to using Rosemary oil but there are also some potential side effects.
Rosemary oil should never be internally consumed or ingested in any way. Rosemary oil can be toxic if taken orally because it contains camphor and other toxic chemicals. If taken orally rosemary oil can cause epileptic convulsions, kidney damage, digestive problems, and death. Because of this, rosemary oil should only be used externally. If Rosemary oil is ingested seek medical attention immediately.
Blood Sugar Levels
Rosemary oil may raise blood sugar levels, but can be dangerous in patients with diabetes or hypoglycemia. If you have diabetes or hypoglycemia ask your doctor before using rosemary oil. If you are using rosemary oil and suspect it may be raising your blood sugar, check it immediately and if so, contact a physician.
According to herbs2000.com, rosemary oil can cause dermatitis, or other skin problems.
If you use rosemary oil and have an allergy to it, you could develop a rash or even have an asthma attack.
Rosemary oil has been known to cause hair growth. This may be a good thing if you desire longer hair. If this is not your intention, then being aware of the possibility may be good to know before you choose to apply rosemary oil to the scalp or use it in a bath.
Even though it has not been studied often, musculoskeletal effects may be linked to the use of rosemary oil.
References and Resourcesherbs2000: Rosemary
University of Maryland Medical Center: Rosemary