Aromatherapy

The routes are direct and well understood, which is unusual among the gentler therapies.

• A direct line to emotion

  Smell is the only sense that reaches the limbic system — the brain's emotion and memory centre — without being relayed through the thalamus first. That anatomical shortcut is why a scent can change how you feel within seconds.

• Memory and association

  Odour recalls context powerfully. A scent linked to safety and home does real work in a hospital room, and the same mechanism explains why a scent linked to a bad infusion can become intolerable.

• Modest pharmacology

  Some compounds have measurable effects — menthol and ginger on nausea pathways, certain constituents on smooth muscle and on skin sensation. These are genuine but small.

• A ritual with a beginning and an end

  Applying a scent before sleep or before a procedure creates a cue the body learns to respond to. Much of the observed benefit works this way, and that is not a criticism.

• Carried by touch

  Applied in massage, the oil and the touch reinforce one another. Most trials of aromatherapy in serious illness are actually trials of aromatherapy massage.

The effect is real but modest and short. Aromatherapy is best used for specific moments rather than as a treatment for a persistent problem.

• Anxiety, especially before procedures

  Inhalation in a waiting room or before a scan. Works within minutes, which is exactly what that moment needs.

• Nausea

  Peppermint and ginger inhalation have modest evidence as an addition to anti-sickness medication. Note the important exception in the cautions below.

• Sleep

  Lavender at bedtime has small but consistent support, and works well as part of a wind-down routine rather than on its own.

• Low mood and a clinical environment

  The smell of a hospital or sickroom is itself demoralising. Changing it is a small intervention with a disproportionate effect on how a room feels.

• Very frail people

  Requires nothing: no movement, no attention, no speech. Sometimes the only therapy still possible.

• Alongside massage

  Where most of the evidence actually sits. The combination outperforms either component in most trials.

Especially worth considering if

• You need something that works in the next five minutes.
• You want something a family member can do at home, cheaply.
• Sedating medication is already at its limit.
• Your room smells of illness and hospital, and that is affecting you more than you expected.

Aromatherapy has the widest gap between its gentle reputation and its actual risks. Essential oils are concentrated, they are shared with everyone in the room whether they consented or not, and one badly timed session during chemotherapy can permanently ruin a scent for someone.

Stop — clearance needed first

Do not start until your medical team has confirmed it is safe for you.

• Asthma, COPD or any reactive airway disease

  Inhaled oils and diffusers can trigger bronchospasm. This is the most common serious problem with aromatherapy and it is regularly overlooked. Needs your doctor's agreement, and testing on a single tissue before any diffuser is used.

• During or immediately after chemotherapy infusion

  Do not introduce a new scent around infusions. Taste and smell distortion plus nausea creates a learned aversion, and the scent — often one you loved — becomes a trigger for nausea for years. Only use scents you are willing to lose.

• Epilepsy or a seizure history

  Camphor-rich oils including rosemary, eucalyptus, sage, fennel and hyssop are traditionally avoided. Ask before using any oil if you have seizures.

• Broken skin, ulcers, radiotherapy skin reactions, graft-versus-host disease

  Nothing is applied to compromised skin. Inhalation only until the skin has healed and your team agrees.

• Pregnancy and infants

  Several oils are avoided in pregnancy. Eucalyptus and peppermint must never be applied near the face of an infant or young child — they can cause breathing difficulty.

• Hormone-sensitive cancers

  A weak estrogenic effect has been debated for lavender and tea tree with repeated topical use. The evidence is not strong, but check with your oncologist rather than assuming it is settled.

Proceed, with changes

These do not rule the therapy out. They change how it is delivered — tell us so we can adapt it.

• Never swallow essential oils

  Ingestion causes serious poisoning and liver injury and has killed people, including children. Nothing on this page is ever taken by mouth, regardless of what a seller online claims.

• Always dilute for skin

  Roughly 1–2% in a carrier oil for adults, and 0.5–1% for frail, elderly or very ill people. Undiluted oil on skin causes chemical burns and sensitisation.

• Patch test first

  A small area, 24 hours, before wider use. Sensitisation can develop suddenly to an oil you have used for years.

• Citrus oils and sunlight

  Bergamot, lime and several other citrus oils are phototoxic — they cause burns and permanent pigmentation on skin exposed to sun. Do not apply to skin that will see daylight.

• Shared rooms and other people

  A diffuser imposes on everyone present, including staff and other patients. One person's comfort is another's migraine or nausea. Personal inhalers are preferred in shared spaces.

• Smell distortion during treatment

  Chemotherapy changes smell perception unpredictably. A favourite scent may become disgusting. Always offer, never impose, and re-check preferences often.

• Confusion, dementia or reduced consciousness

  The person cannot tell you a scent is distressing. Watch the face and breathing, use very small amounts, and stop at any sign of discomfort.

• Fire and heat sources

  Oils are flammable and candle burners are a real fire risk around oxygen, bedding and a person who cannot move quickly. Use electric diffusers or a tissue.

• Oxygen therapy

  No oil-based products near oxygen, and no naked flames. Ask your team what is permitted with your equipment.

Medicines, devices and interactions

Bring your full medication list, including anything bought without a prescription.

• Skin absorption is real

  Compounds applied to skin do enter the bloodstream in small amounts. It is a small effect, but it is not zero, and it is why dilution and skin condition matter.

• Anticoagulants

  Wintergreen and birch contain a salicylate related to aspirin and should be avoided with blood thinners. Check any unfamiliar oil rather than assuming it is inert.

• Topical prescribed medication

  Do not apply oils over medicated patches or prescription creams. Absorption can be altered.

• Sedatives

  Relaxing scents add to drowsiness in some people. Relevant mainly for falls risk when getting up at night.

• G6PD deficiency

  Menthol-containing products should be avoided. Worth knowing about in Indonesia, where G6PD deficiency is not rare.

Before

• A conversation about asthma, allergies, skin condition, current treatment, and — importantly — what smells you currently cannot stand.
• You smell each option from a tissue before anything is diffused or applied. Nothing is chosen for you.
• A patch test if anything is going onto your skin.

During

• Inhalation: a few drops on a tissue or a personal inhaler, two to three slow breaths, repeated as needed. Five to ten minutes is plenty.
• Topical: heavily diluted oil applied to hands, feet, shoulders or temples, often as part of a massage.
• Diffusers, if used at all, run for 15–30 minutes and not continuously.
• Effects on mood and nausea are usually noticeable within minutes.

After

• The effect lasts minutes to an hour or two. It is a moment, not a treatment course.
• Occasionally a headache or nausea from a scent that seemed pleasant at first — stop using that one.
• Any redness, itching or rash means stop immediately and wash the area with soap and water.

Evaluate in the moment, and evaluate honestly. This is a small effect used well, and a small effect used badly is just an expensive smell.

Signs it is helping

• Anxiety measurably lower in the ten minutes after inhalation — before a scan, for instance.
• Nausea eased enough to eat or drink something.
• Settling to sleep more easily with a bedtime routine that includes it.
• The room feels less like a sickroom, and visitors say so too.
• A family member has something practical they can do, and does it.

Pause and tell us if

• Any wheeze, cough, chest tightness or breathlessness — stop the diffuser and ventilate the room. Seek medical help if breathing does not settle.
• Skin redness, itching, blistering or rash.
• Headache or nausea that appears with the scent.
• The scent has become associated with treatment and now triggers nausea — retire it permanently and do not try to push through.
• Anyone else in the room is affected.

Length of a session

Inhalation: 2–3 breaths from a tissue or inhaler, as needed, up to several times a day. Diffusion: 15–30 minutes, not continuous.

Initial course

No course. Aromatherapy is used at specific moments — bedtime, before procedures, when nausea rises.

Continuing

Ongoing use is fine. Rotate oils occasionally, as sensitisation can develop with prolonged daily use of the same one.

When we review it

Whenever treatment changes, whenever smell perception changes, and whenever the scent stops working or starts to grate.

• Let the person choose the scent

  A scent someone dislikes is worse than no scent, and preference cannot be predicted. Always offer two or three from a tissue and let them pick.

• Do not attach a scent to chemotherapy

  The single most important rule here. Conditioned nausea to a favourite smell is a lasting, avoidable harm — keep your comforting scents for days that are not infusion days.

• Use a tissue or personal inhaler, not the room

  Targeted, controllable, respects everyone else present, and easy to stop instantly if it turns unpleasant.

• Dilute more than you think you need

  For someone frail or elderly, half the usual concentration. Stronger is not better, and it is how skin reactions happen.

• Buy from a reputable supplier

  Adulteration is common in the essential oil market. Look for the botanical name and country of origin on the label; be wary of anything sold with health claims.

• Never take oils internally, whatever you are told

  Online sellers promoting ingestion are promoting a genuinely dangerous practice, particularly with children in the house.

• Check the room, not just the patient

  Family, other patients, and staff all breathe the same air. Ask before diffusing anywhere shared.

• Use it as a cue, not just a smell

  Paired consistently with a wind-down routine or with slow breathing, the scent becomes a trigger for the calming response itself — which is where most of its usefulness lives.

Evidence is genuine but modest. The most consistent findings are short-term reductions in anxiety, especially before procedures, and modest benefit for nausea from peppermint and ginger inhalation as an addition to standard anti-emetics. Lavender for sleep has small, consistent support. Much of the stronger evidence in cancer and palliative populations comes from aromatherapy massage, where the touch is doing part of the work. Effects are short-lived, and reviews generally conclude the benefit is real but small. Adverse effects — respiratory triggering, skin sensitisation, and conditioned nausea — are underreported relative to how often the therapy is used. There is no evidence essential oils treat any disease, and claims that they do are common and should be treated with suspicion.

Sources informing this page

• Cochrane reviews — aromatherapy and aromatherapy massage for anxiety and symptom relief in palliative and cancer care
• Society for Integrative Oncology / ASCO — integrative oncology guidance
• US National Center for Complementary and Integrative Health (NCCIH)
• National poisons centre reporting on essential oil ingestion and paediatric exposure

Named for transparency about where our position comes from. Specific study references are added by our clinical team at review.

Take these to your doctor before you start. They are the questions that change what is safe for you specifically.

• “With my asthma or lung condition, is inhaled aromatherapy safe for me at all?”
• “Is my skin currently suitable for anything applied topically?”
• “Are there oils I should avoid given my seizures, my cancer type or my blood thinner?”
• “Is it safe to use a diffuser around my oxygen equipment?”
• “Should I avoid scents entirely around my infusion days?”