Peanut is rare in medication. A 2019 analysis of 42,052 oral medications in the journal Science Translational Medicine found peanut oil in just 0.08% of them. When it does appear, it may not say “peanut” the way you expect: in European and British labeling, peanut oil is called arachis oil. And the food-law rule that treats highly refined peanut oil as a special case has no counterpart for medicine, where there is no food allergen labeling rule at all.
Where peanut shows up in medicine
Peanut oil is used as an oily carrier, the liquid a drug is dissolved in. In US labeling, examples include some oral capsules and at least one oil-based injection given deep into a muscle. In both cases the prescribing information names the peanut oil and warns about peanut allergy, which is the reassuring part: when a label spells it out, the information is there to be found.
Rare is not zero, though, and a warning buried in a package insert only helps if someone reads it. If you have a peanut allergy, it belongs on every pharmacy profile and every medical intake form, stated by name, so the check happens before the first dose. Our food allergies overview covers how peanut fits alongside milk, soy, and wheat in medication.
One hospital-specific note: labels for some intravenous fat emulsions used in hospital nutrition list a known peanut allergy as a reason not to use them, even though they contain no peanut, so mention the allergy to the hospital team.
Arachis oil: the name to know
Arachis is the botanical name of the peanut plant’s genus. The European Medicines Agency lists the ingredient as “arachis oil (peanut oil)”, and its labeling guideline calls for every medicine containing it, by any route, to state in the patient leaflet that it contains arachis oil and should not be used by anyone allergic to peanut or soy (the leaflet says “soya”). US labels usually use the plain name, peanut oil. So “arachis” is most likely to matter if you buy medicine abroad, receive an imported product, or read European or British product information online.
Why Europe warns even about purified oil
Why refined and unrefined peanut oil are different
A peanut allergy is a reaction to peanut protein, not to fat. Oil is mostly fat, and how much protein it carries depends on how it was processed. In data summarized by the FDA, crude peanut and sunflower oils contained 100 to 300 micrograms of protein per milliliter, while the most highly refined oils contained 0.2 to 2.2.
That difference shows up in people. In a double-blind study published in 1997, none of 60 peanut-allergic participants reacted to refined peanut oil, while 6 of the 60 reacted to crude oil. Refined oil is not a guarantee for the most sensitive individuals, but crude or lightly processed oil is a different product. The same refined-versus-crude logic applies to soybean oil, covered in our soy guide.
The refined-oil rule that stops at the pharmacy
Federal food law defines a “major food allergen” to include peanuts and tree nuts, and any food ingredient containing protein from them, but it excludes “any highly refined oil” made from those foods and any ingredient derived from such an oil. That is why a packaged food made with highly refined peanut oil does not have to declare peanut.
None of that reaches your medicine cabinet. The FDA states that its food allergen labeling requirements do not apply to drugs or cosmetics. A drug label may name the oil among its ingredients, but no rule requires it to be flagged as an allergen, refined or not. Our guide to why medication labels do not have to list allergens explains that gap in full.
Tree nuts: almond oil, and where coconut now stands
Peanuts are legumes, not nuts, but the allergies overlap: between 25 and 40 percent of people allergic to peanuts also react to at least one tree nut, according to the American College of Allergy, Asthma and Immunology (ACAAI). For tree nuts, the ingredient worth knowing is almond oil, which turns up in creams, ointments, and other products applied to the skin. Tree nut oils can carry nut protein, and the ACAAI advises people with a tree nut allergy to avoid lotions, hair care products, and soaps that contain them. Skin exposure is not trivial: one published case described an infant with eczema who appears to have become sensitized to almond through almond oil applied to her skin for two months, without ever eating almond. So read the ingredients on creams and ointments too, not only on pills.
Coconut changed status recently. In its revised food allergen guidance published January 6, 2025, the FDA no longer lists coconut among the tree nuts treated as major food allergens, although coconut must still be named in a food’s ingredient list. Botanically, coconut is a fruit, and most people with a tree nut allergy can safely eat it. If you have a tree nut allergy, talk to your allergist before assuming coconut is fine for you. For medicine, the change makes little practical difference: drug labels were never required to flag tree nuts in the first place.
How to check a medication for peanut or tree nut
- Read for the oil names: peanut oil, arachis oil, and almond oil in the inactive ingredients.
- Look for the warning. Some products formulated in peanut oil carry a peanut warning in the prescribing information, which you rarely see; ask your pharmacist to check it for you.
- Be extra careful with medicine from abroad, where the label may say arachis oil.
- Include creams and ointments when you ask about tree nut oils, not just tablets and capsules.
- Do not stop anything on your own. If a medicine you already take turns out to contain a nut oil, review it with your prescriber or pharmacist; for a severe allergy, bring in your allergist.
- Check the product with the app. AllergenMeds flags ingredients like these in the exact product you look up, so you know what to confirm. For another oil that shows up in medicine, see our sesame guide.
Common questions
Do any medications contain peanut?
A few do, as peanut oil. A 2019 study of 42,052 oral medications found peanut oil in 0.08% of them, so it is rare. In the US it is used as an oily carrier in some oral capsules and at least one injection given into a muscle, and the prescribing information for those products warns about peanut allergy.
What is arachis oil?
Arachis oil is peanut oil. Arachis is the botanical genus of the peanut plant, and arachis oil is the name used in European and British medicine labeling. US labels usually say peanut oil, but you may see arachis oil on a medicine bought abroad or on an imported product.
Is refined peanut oil safe for a peanut allergy?
Usually, but not always. Peanut allergy is a reaction to peanut protein, and refining removes most of it. In a double-blind study, none of 60 peanut-allergic people reacted to refined peanut oil, while 6 reacted to crude oil. European regulators still note that purified peanut oil may contain peanut protein, so anyone with a severe allergy should confirm with their pharmacist or allergist.
Do drug labels have to warn about peanuts or tree nuts?
Not as a rule. US food labels must declare peanuts and tree nuts, but FDA says those allergen labeling requirements do not apply to drugs. The ingredient list of a medicine may name the oil, and some products formulated in peanut oil add a warning, but there is no general requirement to flag nut-derived ingredients as allergens.
Is coconut a tree nut?
Not for US food allergen labeling anymore. In January 2025, FDA revised its food allergen guidance and removed coconut from its list of tree nuts, though coconut must still be named in the ingredient list. Coconut is botanically a fruit, and most people with a tree nut allergy can eat it, but check with your allergist first.
Can almond oil in a cream cause a reaction?
It can in some people. The American College of Allergy, Asthma and Immunology notes that tree nut oils may contain nut protein and advises people with a tree nut allergy to avoid lotions, hair care products, and soaps that contain them. Check the ingredients on creams and ointments, not just on pills.
Sources
- FDA: Approaches to Establish Thresholds for Major Food Allergens (refined oil exemption and protein levels in crude vs. refined oils)
- FDA: Food Allergies (what the allergen labeling requirements cover, and what they do not)
- FDA: Frequently Asked Questions on the Food Allergen Labeling Guidance (coconut and the revised tree nut list)
- European Medicines Agency: Annex on excipients in the labeling and package leaflet (arachis oil)
- American College of Allergy, Asthma and Immunology: Tree Nut Allergy
This guide is for education only, not medical advice. Always talk to your doctor or pharmacist before starting, stopping, or switching any medication.