Essential Oils for Colds and Flu: What the Evidence Supports, and the Safety Risks for Children and Pets

Each cold and flu season brings recommendations to diffuse, inhale, or apply essential oils such as eucalyptus, peppermint, tea tree, lavender, and oregano to stay healthy or recover faster. Some of these oils have pleasant aromas and can make breathing feel easier when congested, and certain oil-based products have been tested in clinical trials for symptom relief. But claims that essential oils prevent infections or boost immunity go beyond the evidence, and some oils can be dangerous, especially for young children and pets.

This article reviews what research shows about essential oils for colds and flu, which uses have some support, the safety risks, and evidence-based ways to prevent and manage respiratory infections.

Do essential oils help prevent or treat colds and flu? There is no good evidence that essential oils prevent colds or flu or shorten them. Some, like peppermint, menthol, and eucalyptus, may ease symptoms such as congestion, and steam inhalation can feel soothing. But oils can cause allergic reactions, are dangerous if swallowed, and are especially risky for children and pets. Vaccination, handwashing, and rest remain the proven approach.

What Essential Oils Are

Essential oils are concentrated aromatic compounds extracted from plants, usually by steam distillation or cold pressing. A single bottle may contain the oil from large quantities of plant material, making them far more potent than the herbs themselves. Their main components, such as 1,8-cineole in eucalyptus, menthol in peppermint, terpinen-4-ol in tea tree, and carvacrol in oregano, have biological activity in laboratory studies, including antimicrobial and anti-inflammatory effects at certain concentrations. Essential oils are sold largely as cosmetics or aromatherapy products, which are not reviewed by the FDA for effectiveness in treating or preventing disease.

The National Center for Complementary and Integrative Health notes that aromatherapy has been studied for various uses, such as sleep and anxiety, but that little rigorous research exists for many claimed benefits, and it cautions about safety issues including skin irritation and toxicity if oils are swallowed.

Can Essential Oils Prevent Colds or the Flu?

No. There is no reliable evidence that essential oils prevent respiratory infections, and inhaling or diffusing them does not stop viruses from spreading or infecting you. Many articles claim that diffusing essential oils “purifies the air,” kills viruses, or strengthens the immune system. In laboratory dishes, some essential oils inhibit bacteria and certain viruses at high concentrations. These conditions differ greatly from a room where oil is diffused at low concentrations, or from the inside of the respiratory tract, where viruses infect cells. No well-designed clinical trials have shown that diffusing, inhaling, or applying essential oils reduces the chance of catching a cold or flu. Relying on them for protection could lead people to neglect measures that do work.

Do Essential Oils Help With Cold and Flu Symptoms?

Some may offer modest symptom relief: peppermint and menthol can create a sensation of easier breathing, and eucalyptus is a common ingredient in chest rubs, though evidence for faster recovery is weak. A 2010 randomized trial in Pediatrics by Ian Paul and colleagues compared a vapor rub containing camphor, menthol, and eucalyptus oils with petrolatum and with no treatment in 138 children aged 2 to 11 with colds. Parents rated the vapor rub most favorably for relieving nighttime cough, congestion, and sleep difficulty, and the children and parents slept better, though some children had mild skin or eye irritation. Vapor rubs work partly by creating a cooling sensation that makes breathing feel easier; they do not shorten the infection. Labels advise against use in children under two, and products should never be applied under the nose or near the eyes of young children or heated in a microwave.

A 2000 multicenter randomized, double-blind, placebo-controlled trial by Heinrich Matthys and colleagues tested a standardized extract of plant oils (myrtol standardized, containing cineole, limonene, and alpha-pinene) in adults with acute bronchitis. Patients taking the extract recovered more quickly and completely than those taking placebo, with results comparable to an antibiotic and a mucus-thinning drug. This product is a standardized, regulated medicine in some countries, not the same as household essential oils, and it was taken in specific doses in capsule form designed for that purpose.

Steam inhalation, with or without a few drops of eucalyptus or menthol oil, may make congested people feel more comfortable, but trials of steam inhalation have not shown that it speeds recovery, and hot water can cause burns, particularly in children.

Are Essential Oils Safe to Use?

Essential oils are not harmless: they can cause skin reactions and allergies, are toxic if swallowed, can trigger asthma, and are especially dangerous for infants, young children, and pets. Because essential oils are concentrated, they can cause harm in small amounts, especially if swallowed. The National Capital Poison Center warns that swallowing eucalyptus oil can cause seizures, that sage and other oils have caused seizures in children, that camphor is dangerous if ingested, and that swallowing wintergreen oil is roughly equivalent to swallowing a large number of adult aspirin tablets. A 2001 review in Paediatrics & Child Health by Zbigniew Flaman and colleagues at the Hospital for Sick Children in Toronto described how camphor and eucalyptus oils can be absorbed through the mouth and skin and can be harmful, even life-threatening, when young children ingest them.

Other risks include skin irritation and allergic reactions, especially with undiluted oils or oils such as tea tree, cinnamon, and oregano; photosensitivity with some citrus oils; and respiratory irritation in people with asthma when oils are diffused. Pets are also at risk: cats are particularly sensitive to many essential oils because they lack certain liver enzymes, and diffused or topically applied oils have caused poisoning in cats and dogs.

Hormonal Effects of Lavender and Tea Tree Oil

Some essential oils may have effects beyond irritation. A 2007 report in the New England Journal of Medicine by Derek Henley and colleagues described three prepubertal boys who developed breast enlargement (gynecomastia) after using products containing lavender and tea tree oils; the condition resolved after they stopped using the products. Laboratory experiments showed that the oils had weak estrogen-like and anti-androgen activity. Later research has continued to examine these effects. While the absolute risk is low, these findings suggest caution with frequent use of such products on young children.

Common Essential Oils and Their Risks

Oil	Common cold-season use	Key safety concerns
Eucalyptus	Inhalation for congestion; in vapor rubs	Seizures if swallowed; avoid near infants’ faces
Peppermint	Inhalation, chest rubs	Menthol can cause breathing problems in infants
Camphor	Vapor rubs	Highly toxic if swallowed; seizures in children
Tea tree	Diffusing, topical use	Toxic if swallowed; skin allergy; toxic to cats
Oregano	Promoted as “natural antibiotic”	Strong skin and mucous membrane irritant
Wintergreen	Muscle aches	Salicylate poisoning if swallowed

Why Laboratory Results Can Mislead

Many claims about essential oils cite laboratory studies showing that an oil kills bacteria, fungi, or viruses in a dish. These studies typically expose microbes directly to oils at concentrations far higher than could safely be achieved in the human body or in room air, and they often test bacteria rather than the viruses that cause colds and flu. Respiratory viruses infect cells lining the nose and airways, where an inhaled scent reaches only trace amounts. In addition, compounds that damage microbes at high concentrations can also damage human cells. Translating laboratory results into health claims requires clinical trials in people, which have not shown that essential oils prevent respiratory infections.

Diffusers and Indoor Air

Diffusers release volatile organic compounds into indoor air. In well-ventilated rooms with brief use, levels are usually low, but continuous diffusion in small, closed spaces can raise concentrations and may irritate the eyes, nose, and airways. Some essential oil components, such as limonene and pinene, react with ozone in indoor air to form secondary pollutants, including small amounts of formaldehyde and fine particles. People with asthma may experience symptoms when oils are diffused nearby. Using diffusers intermittently, keeping rooms ventilated, and avoiding diffusion in bedrooms of infants or people with respiratory conditions reduces these concerns.

Is Oregano Oil a Natural Antibiotic?

Oregano oil kills bacteria in laboratory dishes, but that does not mean it works as an antibiotic in the body; there is no clinical evidence it treats infections, and it can irritate tissues. Oregano oil is often marketed as a natural antibiotic for colds and flu. Its main components, carvacrol and thymol, have antimicrobial activity in laboratory studies. However, colds and flu are caused by viruses, against which antibiotics, natural or not, are ineffective, and there are no rigorous clinical trials showing that oregano oil prevents or shortens these infections. Concentrated oregano oil can irritate the mouth, throat, and digestive tract and should not be applied undiluted to skin. Capsules sold as supplements are not standardized, and their contents can vary widely.

Are Essential Oils Safe During Pregnancy and Breastfeeding?

Many essential oils are not recommended during pregnancy or breastfeeding because safety data are limited and some may pose risks, so pregnant and nursing people should consult a clinician before using them. Safety data on essential oils during pregnancy and breastfeeding are limited. Some oils, such as pennyroyal, are known to be toxic, and others contain compounds that could affect pregnancy at high doses. Most experts advise avoiding ingestion of essential oils during pregnancy, using only diluted oils topically in small amounts if at all, and discussing aromatherapy with a clinician. Applying oils to the breast area while breastfeeding should be avoided because infants may ingest them.

Key Facts at a Glance

No rigorous trials show that essential oils prevent colds or flu. A 2010 trial of 138 children found that a vapor rub containing camphor, menthol, and eucalyptus oils relieved nighttime cough, congestion, and sleep difficulty better than petrolatum or no treatment. A 2000 trial found a standardized plant oil extract improved recovery from acute bronchitis compared with placebo. Swallowing eucalyptus, camphor, sage, or wintergreen oils can cause seizures or poisoning in children. A 2007 report linked lavender and tea tree oil products to reversible breast enlargement in three prepubertal boys. Many essential oils are toxic to cats.

Using Essential Oils More Safely

Never swallow essential oils unless a product is specifically formulated and labeled for oral use under medical guidance.

Store oils locked away from children and pets, in child-resistant containers.

Dilute before applying to skin and test a small area first; avoid use on broken skin.

Be cautious with children. Do not apply menthol or camphor products to children under two, and keep oils away from infants’ faces.

Diffuse briefly in ventilated rooms, and avoid diffusing around people with asthma, infants, or pets, especially cats and birds.

Call poison control immediately if a child swallows an essential oil, even if they seem fine.

What Actually Helps Prevent Colds and Flu

The most effective prevention measures are well established: annual influenza vaccination and other recommended vaccines, frequent handwashing with soap and water or using alcohol-based sanitizer, avoiding touching the face, staying home when sick, covering coughs and sneezes, improving indoor ventilation, and maintaining general health through sleep, physical activity, and a balanced diet. For symptom relief, rest, fluids, honey for cough in people over one year, saline nasal rinses, and appropriate over-the-counter medicines for adults can help. People at high risk of flu complications should contact a clinician early, since antiviral medications work best when started soon after symptoms begin.

Children and Essential Oils: Practical Guidance

Pediatric experts advise particular care with essential oils around children. Keep bottles out of reach and sight, since many oils smell appealing and come in small bottles that resemble medicine or flavorings. Do not apply oils near a child’s face, especially products containing menthol, camphor, or eucalyptus, which can trigger breathing problems in infants. Avoid using essential oils on children under two except in products designed and labeled for that age. For older children, use well-diluted oils on limited skin areas and watch for irritation. If a child swallows an essential oil, contact poison control right away, even if no symptoms appear, because effects such as seizures can develop within hours.

Pets and Essential Oils

Cats are especially vulnerable to essential oils because they lack certain liver enzymes needed to break down compounds such as phenols and terpenes. Oils including tea tree, eucalyptus, peppermint, wintergreen, cinnamon, citrus, and pine have been associated with poisoning in cats, causing drooling, vomiting, tremors, difficulty walking, and liver damage. Dogs can also be poisoned, particularly by tea tree oil applied to their skin. Birds are sensitive to airborne irritants. Pet owners should avoid applying oils to pets without veterinary advice, keep diffusers out of rooms where pets spend time, and contact a veterinarian or animal poison control center if a pet shows symptoms after exposure.

Evidence-Based Cold and Flu Care

For most healthy adults and children, colds resolve within about a week to ten days with supportive care: rest, fluids, and symptom relief. Honey can ease cough in people over one year. Saline nasal sprays or rinses can relieve congestion. Over-the-counter pain relievers can reduce fever and aches, used according to label directions. Antibiotics do not help viral colds or flu. For influenza, antiviral medications can shorten illness and reduce complications when started early, particularly in high-risk groups such as young children, older adults, pregnant people, and those with chronic conditions. Seek medical care for difficulty breathing, chest pain, persistent high fever, dehydration, or symptoms that improve and then worsen.

How Essential Oils Are Regulated

In the United States, essential oils occupy a regulatory gray area. Sold for aroma or as cosmetics, they are not reviewed by the FDA for effectiveness. If marketed with claims to treat, cure, or prevent disease, they would be considered drugs requiring approval, and the FDA has sent warning letters to companies making such claims, including claims that oils could prevent or treat COVID-19 or flu. Products sold as dietary supplements for ingestion must meet supplement rules but are not approved for safety or effectiveness before sale. Quality varies, and some products have been found to be adulterated or diluted. Child-resistant packaging requirements apply to certain oils, such as wintergreen, because of poisoning risks.

Common Myths

“Natural oils are always safe.” Many essential oils are toxic if swallowed and can irritate skin and airways.

“Diffusing oils kills viruses in the air.” There is no evidence that home diffusion prevents infections.

“Therapeutic grade means medical quality.” “Therapeutic grade” is a marketing term, not a regulated standard.

“Essential oils can replace flu shots.” Vaccination is the most effective way to prevent influenza and its complications.

Questions to Ask Before Using an Essential Oil Product

What is the oil, and what concentration is in the product? Is it intended for inhalation, skin application, or ingestion? Is it appropriate for children, pregnant people, or people with asthma in your household? Are there pets in the home that could be exposed? Does the product make claims to treat or prevent disease, which would be a red flag? Is the container child-resistant, and can it be stored securely? Answering these questions helps people enjoy aromatherapy while avoiding the most common risks.

Vapor Rubs: Using Them Correctly

Vapor rubs containing camphor, menthol, and eucalyptus oil can be helpful for children over two and adults when used as directed: rub a thin layer on the chest and throat, not under the nose or on broken skin, and keep the product away from the eyes and mouth. Never heat vapor rubs or add them to hot water, which can cause burns, and do not let children swallow them, since camphor is toxic. Some products formulated for infants omit camphor and menthol; follow product labels and pediatric advice.

Essential Oils in Hospitals and Clinical Settings

Some hospitals offer aromatherapy as a complementary therapy, typically for comfort, anxiety, or nausea, using inhaled oils such as lavender or peppermint under protocols that address safety. Small studies have examined aromatherapy for postoperative nausea and anxiety with mixed results, and reviews generally describe the evidence as limited or low quality. These clinical uses differ from claims about preventing infections, and hospitals using aromatherapy usually avoid diffusers in shared spaces because of potential effects on other patients and staff.

Peppermint and Menthol

Menthol, the main component of peppermint oil, activates cold-sensing receptors in the nose, creating a sensation of cooler, easier airflow even though it does not actually open the airways. This is why menthol lozenges, rubs, and inhalers can make congested people feel better. However, menthol can cause breathing difficulties, including reflex slowing of breathing, in infants, which is why products containing menthol are not recommended for young children. In adults, peppermint oil taken in enteric-coated capsules has been studied for irritable bowel syndrome, a separate use from cold relief.

Tea Tree Oil Uses With Evidence

Tea tree oil has more research behind it for skin conditions than for respiratory infections. Diluted tea tree oil has shown some benefit for mild acne and certain fungal skin infections in small trials. It is toxic if swallowed, can cause allergic contact dermatitis, and, as noted above, has been linked with hormonal effects in a small number of boys. Applying undiluted tea tree oil to skin or using it in the nose or ears is not recommended.

Further Reading

The National Center for Complementary and Integrative Health summarizes research on aromatherapy and specific oils. Poison control centers provide guidance on essential oil safety and what to do after exposures. The CDC offers guidance on preventing respiratory infections, including vaccination recommendations.

Key Terms

Essential oil: A concentrated aromatic extract from plants.

Aromatherapy: The use of plant aromas for well-being.

Camphor: A compound in some vapor rubs that is toxic if swallowed.

1,8-cineole: The main component of eucalyptus oil, with decongestant-like sensory effects.

Dilution: Mixing an essential oil with a carrier oil to reduce skin irritation.

The Bottom Line

Essential oils can provide pleasant aromas and some products, such as vapor rubs, have evidence for easing cold symptoms like nighttime cough and congestion in children over two. But there is no good evidence that essential oils prevent colds or flu, and swallowing them can be dangerous, particularly for young children. Some oils affect the skin, airways, hormones, and pets. Vaccination, handwashing, staying home when sick, and good ventilation remain the most effective prevention measures, while rest, fluids, honey for cough, and appropriate medicines provide relief when illness strikes.

Children’s Exposures Have Risen

As essential oils have become more popular, poison centers have reported growing numbers of calls about children exposed to them, most often from swallowing small amounts from bottles left within reach or from diffuser reservoirs. Many exposures cause mild symptoms such as coughing, vomiting, or mouth irritation, but some lead to drowsiness, seizures, or breathing problems requiring hospital care. Child-resistant caps and flow restrictors help, but they are not foolproof. Storing oils as carefully as medicines and teaching older children not to taste them reduces risk.

A Balanced View

Essential oils are neither miracle cures nor inherently dangerous when used carefully. Their scents can be pleasant and relaxing, and certain formulated products relieve symptoms. The problems arise from exaggerated claims that they prevent infections, which can lead people to skip proven measures, and from unsafe use, particularly ingestion and exposure of young children and pets. Treating essential oils as potent chemicals rather than harmless natural products, and relying on evidence-based prevention and care for colds and flu, allows people to enjoy them while staying safe.

Essential Oils and Asthma

People with asthma or other chronic lung conditions may react to strong scents, including essential oils diffused indoors. Symptoms can include coughing, wheezing, and chest tightness. Some workplaces and schools have fragrance-free policies for this reason. If someone in the household has asthma, avoid diffusing oils or use them only briefly in a separate, well-ventilated room, and watch for symptoms. People with asthma should not rely on essential oils to treat breathing problems and should follow their asthma action plan.

Choosing Quality Products

If you use essential oils, buy from reputable suppliers that list the plant’s botanical name, the part of the plant used, the country of origin, and the extraction method. Some suppliers provide gas chromatography test results showing composition and purity. Store oils in dark glass bottles away from heat and light, since oxidized oils are more likely to cause skin reactions. Be skeptical of products claiming to treat diseases, labeled with vague terms like “therapeutic grade,” or sold with instructions to swallow them regularly without medical guidance.

Steam Inhalation Safety

Steam inhalation over a bowl of hot water, sometimes with eucalyptus or menthol oil, is a common home remedy. Burn units have reported scald injuries, particularly in children who knock over bowls of hot water. If you use steam, take precautions: use warm rather than boiling water, place the bowl on a stable surface, keep children away, and consider a warm shower as a safer alternative. Evidence suggests steam may make people feel more comfortable but does not shorten colds.

When to See a Doctor

Seek medical care for a cold or flu if symptoms include difficulty breathing, chest pain, confusion, persistent high fever, dehydration, or symptoms that improve then worsen, which can signal a secondary infection. Infants under three months with fever should be seen promptly. Do not delay care by relying on essential oils or other home remedies when these warning signs appear.

People at higher risk of complications, including adults over 65, pregnant people, young children, and those with chronic heart, lung, or immune conditions, should contact a clinician early in a flu illness, since antiviral treatment works best when started within about two days of symptom onset and can reduce the risk of serious complications.

For prevention, staying up to date on recommended vaccines, including annual flu shots and other respiratory vaccines recommended for specific age groups, remains far more effective than any home remedy, and pharmacies, clinics, and health departments offer convenient access during the fall and winter seasons, often at no cost with insurance or through public health programs for those without coverage.

Frequently Asked Questions

Do essential oils prevent colds and flu?

No. There is no reliable evidence that essential oils prevent respiratory infections like colds or the flu. Diffusing or inhaling them does not stop viruses from spreading or protect you from infection. Proven prevention measures remain vaccination against flu, frequent handwashing, avoiding close contact with sick people, and not touching your face.

Can essential oils help with cold or flu symptoms?

Possibly a little. Peppermint and menthol can create a cooling sensation that makes breathing feel easier, and eucalyptus is a common ingredient in chest rubs and steam inhalations that some people find soothing for congestion. However, the evidence that essential oils actually shorten illness or clear infections is weak, so they offer comfort at best.

Are essential oils safe to use?

Not entirely. Essential oils are concentrated plant compounds that can cause skin irritation and allergic reactions, trigger asthma when inhaled, and be poisonous if swallowed. They are especially dangerous for infants, young children, and pets, and some, like eucalyptus and camphor, have caused serious harm in children, so they must be used carefully and kept out of reach.

Is oregano oil a natural antibiotic?

Oregano oil can kill bacteria in laboratory tests, which is why it is marketed as a “natural antibiotic,” but killing germs in a dish does not mean it works safely or effectively inside the body. There is no clinical evidence that it treats infections in people, and taken undiluted it can irritate the mouth, throat, and stomach.

Can children use essential oils for colds?

Caution is essential. Several essential oils, including eucalyptus, peppermint, and camphor, can cause breathing problems, seizures, or poisoning in infants and young children, and should not be applied to or inhaled by them without medical guidance. For children’s colds, safer measures include fluids, rest, saline drops, a humidifier, and advice from a pediatrician.

References

1. Paul IM, Beiler JS, King TS, et al. Vapor rub, petrolatum, and no treatment for children with nocturnal cough and cold symptoms. Pediatrics. 2010;126(6):1092–1099. PMID 21059712
2. Matthys H, de Mey C, Carls C, et al. Efficacy and tolerability of myrtol standardized in acute bronchitis: a multi-centre, randomised, double-blind, placebo-controlled parallel group clinical trial vs. cefuroxime and ambroxol. Arzneimittelforschung. 2000;50(8):700–711. PMID 10994153
3. Flaman Z, Pellechia-Clarke S, Bailey B, McGuigan M. Unintentional exposure of young children to camphor and eucalyptus oils. Paediatrics & Child Health. 2001;6(2):80–83. PMID 20084213
4. National Center for Complementary and Integrative Health. Aromatherapy. nccih.nih.gov
5. National Capital Poison Center. Essential Oils: Poisonous when Misused. poison.org
6. Henley DV, Lipson N, Korach KS, Bloch CA. Prepubertal gynecomastia linked to lavender and tea tree oils. New England Journal of Medicine. 2007;356(5):479–485. PMID 17267908

Last updated: October 6, 2026