Lime Oil: Evidence, Safety and How It Is Used

Safety first. Contact with limes followed by sunlight can cause a phototoxic skin rash (phytophotodermatitis), according to dermatology literature. [1] Lime oil on skin is treated as a similar risk by safety assessments (below). Do not swallow essential oils. If anyone has swallowed any essential oil, call Poison Help at 1-800-222-1222; call 911 for collapse, a seizure or trouble breathing. [2] See Phototoxicity: citrus oils and sunlight.

What lime oil is

Lime oil is an essential oil from the lime. The Global Biodiversity Information Facility (GBIF) lists the accepted plant name as Citrus × aurantiifolia (Christm.) Swingle, family Rutaceae. [3] A 2021 EU animal-feed panel opinion names "lime oil from Citrus aurantiifolia". [4] Common names can cover more than one plant, so check the botanical name on a label; see Reading an essential oil label. This page is information only.

Pressed versus distilled: what sources say

The two main ways to make citrus oils are pressing (cold-pressed or expressed) and distilling. A German food-safety commission reported that distilled and cold-pressed citrus oils differ in their furanocoumarin levels, that the highest levels were likely in products containing lime or bergamot oil, and that no furanocoumarins were found in distilled oils. [5] A 1985 laboratory study found that lime oil and bitter-orange oil contained large amounts of oxypeucedanin, a compound whose phototoxic potency was about one quarter that of bergapten in that study. [6] An EU animal-feed panel in 2021 concluded that lime oil from Citrus aurantiifolia and expressed lemon oil should be considered irritants to skin, eyes and the respiratory tract and as skin sensitisers, and that furocoumarins in the expressed lemon oil may cause phototoxicity. [4]

In a 2007 laboratory test using human red blood cells, lime oil produced moderate UVA-induced haemolysis (breakdown of red blood cells); the authors concluded that some, but not all, fragrances exert phototoxic effects in vitro. [7] That test does not show what happens on a person's skin.

What does this mean for a reader? Pressed lime oil is likely to be more of a sun-reaction concern than distilled lime oil, according to the commission's finding, but our sources do not give a "safe on skin" level, and we cannot tell you which type is in a bottle. If a label does not say, ask the maker, a pharmacist or a clinician. We do not provide a personal use or dilution guide; see Diluting essential oils: what sources say.

Skin reactions

The FDA says certain citrus oils used safely in food can be harmful in cosmetics, particularly on skin exposed to the sun. [8] Dermatology case literature describes phytophotodermatitis, a phototoxic rash from contact with psoralen-containing plants such as celery, limes, parsley, figs and carrots. [1] Limonene is a common fragrance ingredient that readily oxidizes on exposure to air; in a US patch-test study of people with suspected fragrance allergy, 8% (7 of 90 tested) reacted to oxidized limonene. [9] Poison Control says to stop a product that causes a rash and gently wash it off. [2] See Patch testing and what to do after a reaction.

What research shows

Proper evidence not found. We searched PubMed for randomized trials of lime essential oil in people (aromatherapy, skin, anxiety, nausea) and found no trial of lime oil alone that we could read. Aromatherapy trials of "citrus" scents exist, but we did not find one that tested lime oil alone, so no lime-specific claim is made. A meta-analysis of 20 preoperative-anxiety trials named lavender, citrus species and rose preparations as the most commonly used aromas; lime is not named in the abstract. [10]

Safety by group

• Medicines: the sources we read describe no lime oil medicine interactions on skin or in the air. Not described is not proof of none. See How interactions work.
• Pregnancy and breastfeeding, babies and children: no lime-oil advice in our sources. Poison Control says children have thin skin and immature livers, which might make them more susceptible to toxic effects than adults. [2] Ask a clinician. See Essential oils around babies and children.
• Swallowing: Poison Control warns that aspiration can cause pneumonia. [2]
• Surgery: tell the surgical team about oils or supplements; see Before surgery.