Frankincense oil comes from the resin of Boswellia serrata trees. Some aromatherapy oils, perfumes and certain types of incense contain this oil. Ayurvedic medicine, the traditional health care of India, also uses frankincense oil to treat several conditions. In Western medicine, frankincense oil is of interest because of its anti-inflammatory properties, according to the Memorial Sloan-Kettering Cancer Center. Some side effects are possible, but the MSKCC notes that frankincense seems to have fewer negative effects than drugs that treat inflammatory conditions, such as steroids and non-steroidal anti-inflammatory drugs.
Gastrointestinal Side Effects
Gastrointestinal side effects are possible when taking frankincense oil, according to the Physicians' Desktop Reference. They may include an upset stomach, nausea, stomach pain, burning sensations or an unpleasant feeling of fullness. Frankincense oil can also make an upset stomach or stomach pain worse.
Frankincense oil has blood-thinning effects and can increase the risk of abnormal bleeding, as noted by the University of Maryland Medical Center. This is primarily of concern for people with a bleeding disorder, or anyone taking medications or other herbs with anti-coagulant effects, such as warfarin, heparin, ibuprofen, aspirin or ginkgo biloba. Anyone scheduled for a surgical or dental procedure should stop taking frankincense oil beforehand.
Though rare, some people might experience an allergic reaction to frankincense oil. Signs as listed by Physicians' Desktop Reference include a rash or hives, itchy or swollen skin, difficulty breathing, tightness in the throat or chest, and chest pain. An allergic reaction to frankincense oil should be considered a medical emergency.