essential oils

Can Essential Oils Interfere With the Prescriptions You’re Writing?

When you take a patient’s history, are you asking what essential oils they may be using in addition to any medications they’re taking? Patients are often under the impression that because essential oils are derived from natural, plant-based substances, they’re a safe alternative to traditional pharmaceuticals and pose little to no health risk. As such they may not feel it’s relevant to disclose it to their healthcare provider unless asked. 

Unfortunately there aren’t many studies on how essential oils may interact with different medications. But because they do contain high concentrations of active compounds that are metabolized by the body when ingested or applied topically, there is a very real possibility for dangerous drug interactions. If you’re not discussing essential oil usage with your patients, especially those who are on certain medications, you could actually be putting your patient’s health in jeopardy and increasing their risk for serious medical complications.

Here are common interferences between essential oils and prescription medications nurse practitioners need to be aware of.  

Interferences with Surgery

For patients who need surgical intervention, certain essential oils can increase the risk for complications during and after their procedure in a variety of ways. Many common oils have blood thinning properties and thus can increase bleeding risk. Other oils have sedative properties and thus can be dangerous when combined with anesthesia. There are also certain oils that may include substances that adversely interact with post-operative pain medication. Because there is very little research to specify which varieties of oils could pose an elevated risk for surgical complications, it’s in the patient’s best interest that they stop the use of all essential oils at least a week prior to any planned surgeries, including those that are used aromatically.


As mentioned, quite a few oils have blood thinning properties so patients who regularly take anticoagulants such as aspirin, heparin, warfarin, etc., and patients with bleeding disorders, peptic ulcer disease, hemophilia and pregnant patients nearing childbirth should avoid using oils that contain coumarins such as angelica, birch, cinnamon, clove, fir, helichrysum, laurus nobilis, nutmeg, oregano and wintergreen. Eugenol, which is found in clove, thyme and oregano, should also be avoided by patients who are on anticoagulants.


When used on their own, lavender and neroli oil are great options for reducing anxiety and promoting sleep and relaxation. But because they both have mild sedative properties, it’s best that patients do not combine them with other medications that produce similar reactions. Traditional sedatives can also be metabolized much faster when used with rosemary, eucalyptus, ravintsara and bay laurel; so patients should not use these oils along with medications that also have sedating properties.  

Medications Affected by Citrus Fruits

Furanocoumarins, a type of chemical compounds found in certain citrus fruits, can be a major inhibitor of several common prescription drugs due to the presence of 6,7-dihydroxybergamottin (DHB) and bergamottin. Although only small amounts of these constituents can be found in grapefruit oil, lemon oil and other essential oils derived from citrus fruits, there is still the potential for interactions when used by patients on medications such as statins, antihistamines, cough suppressants, benzodiazepines and hypnotics, erectile dysfunction drugs, HIV protease inhibitors, immunosuppressants, and certain hormones (including hormonal birth control pills). It’s best for patients on any one of these medications to avoid grapefruit and lemon oils altogether to avoid the possibility for any harmful interactions.

Antidepressants and Antipsychotics

Patients who take MAOIs, SSRIs and bupropion antidepressants must use extreme caution with essential oils as there are many that can negatively interact with the medications. Patients on MAOIs and SSRIs should avoid oils containing clove or nutmeg as these can increase their risk for possible blood pressure changes, tremors and confusion. They should also stay away from holy basil, bay, blue tansy, cinnamon leaf, melissa, palmarosa and parsley seed. Patients on bupropion antidepressants should not use lemongrass, may chang, honey myrtle, melissa, palmarosa, lemon myrtle and blue tansy.

Oils containing farnesene and alpha-bisabolol constituents such as German chamomile, blue tansy, balsam poplar, and yarrow should be avoided by patients on any kind of antidepressant or antipsychotic medication as these can enhance the effects of these drugs.

Diabetic Medications

Patients who are diabetic must be extremely careful when using essential oils. Some oils can influence blood sugar. Advise diabetic patients to steer clear of essential oils containing anise, star anise, cassia, cinnamon, dill, fennel, geranium, lemongrass, may chang, melissa, myrtle, lemon myrtle, oregano, savory, and turmeric.

Interferences with Cancer Treatments

Aromatherapy can be highly effective in helping manage the restlessness, anxiety and stress associated with conventional cancer treatment but there are also potential interactions between certain oils and cancer therapies. For example, in animal and lab studies, some essential oils used in incorrect doses or too high a concentration have been found to contribute to tumor development. Additionally, certain essential oils can compete with cell receptor sites utilized in chemotherapy, including aromatherapies. Patients who have cancer should consult their oncologist about which essential oils may help complement their treatment as well as those that should be avoided.

Because they do produce real, biochemical reactions within the body, essential oils can be highly effective at treating a variety of conditions. For most people, they are generally safe when used appropriately but for patients on other medications, there is a real risk for interaction. Even if a dose is relatively small, trace amounts of prescription drugs mixed with essential oils can cause powerful interactions, especially with those that produce the same or similar effects. So even though they are naturally occurring, it’s not always safe for a patient on prescription medications to use essential oils simultaneously.