Essential Oil Safety

Essential oils are strong, and natural origin does not make them safe. [1] This page covers the main risks. It is education, not personal medical or veterinary advice.

The short version

• Do not swallow essential oils. Tea tree oil taken by mouth can cause confusion, unsteadiness, inability to walk and coma. [2] We give no advice to swallow any essential oil.
• Do not use undiluted oil on skin. We do not give a universal dilution chart, because the right amount depends on the oil and the person and sources do not give a single rule.
• Keep oils away from young children and pets.
• Stop if you react. Wash the area and ask a pharmacist or clinician.

Skin reactions and allergies

Plants can contain materials that irritate skin or cause allergic reactions. [1] Tea tree oil can cause redness or irritation, more likely if the product is old or has been exposed to heat, light or air. [2] Peppermint oil on skin can cause rashes and irritation. [3] Lavender products on skin may cause allergic reactions. [4]

Sun sensitivity

Certain citrus oils used safely in food can be harmful in cosmetics, particularly when applied to skin exposed to the sun. [1]

Swallowing

Do not swallow essential oils. Tea tree oil is the clearest example in the NIH summary. [2] Mouthrinses containing tea tree oil should not be swallowed. [2] Some capsules containing peppermint oil have been studied, but these are made products, not bottled oil. [3]

Children

• Menthol, found in peppermint oil, should not be inhaled by or applied to the face of an infant or small child, because it may negatively affect breathing. [3]
• NIEHS reports clinical cases linking skin use of essential oils with breast tissue growth in prepubescent boys, and a 2019 case in prepubescent girls using lavender-fragranced products, which resolved when exposure stopped. [5] NIH's NCCIH says it is unclear whether lavender was responsible. [4]
• Keep all oils out of reach, and call for help if a child swallows one (see below).

Hormone-related questions

NIEHS says laboratory tests found that lavender oil, tea tree oil and some of their chemicals showed hormonal activity. These were tests in cell lines in test tubes. They tested several dilutions, and the activity decreased as the dilution increased. Clinical cases have involved skin exposure, not aromatherapy, and more studies are needed to know about inhalation. NIEHS says using essential oils is up to the individual and wants the public to be aware of the findings. [5] It also notes the same chemicals appear in many other oils (for example limonene was found in 90 of 93 oils analysed). [5]

Pregnancy and breastfeeding

NIH says topical tea tree oil products may be safe in pregnancy and breastfeeding, and that little is known about lavender in pregnancy or breastfeeding. [2][4] For most other oils we did not find a source we could read. Ask your clinician before use.

Medicines

NIH notes theoretical reasons that lavender might interact with sedative drugs or herbs, relevant before surgery. [4] Tell your pharmacist or clinician which oils and products you use.

Pets

Pets can be poisoned by essential oils, and cats and dogs differ from people. The only oil we could verify from a veterinary toxicology source is tea tree oil, which Pet Poison Helpline says is toxic to pets at higher concentrations, with even a few concentrated drops on the skin or swallowed able to cause severe poisoning. [6] We did not find readable sourced pages for other oils, so we make no claim that any oil is safe for a pet. Ask a veterinarian before using any oil near or on a pet.

Who to call (US)

• A person: Poison Control, 1-800-222-1222, or the online tool at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing or cannot be woken. [7]
• A pet: ASPCA Animal Poison Control Center, (888) 426-4435 [8], or Pet Poison Helpline, (855) 764-7661; the Pet Poison Helpline site says an incident fee applies. [9] You can also go to a veterinarian or emergency clinic.
• Numbers for other countries are not listed here because we have not verified them.

Regulation and claims

The FDA treats claims that a product will treat disease, ease pain or help you sleep as drug claims, and drugs need FDA approval for safety and effectiveness. [1] A bottle of essential oil is not a medicine approved to treat anything.