Eucalyptus in the shower: what it does, and what it does not

A bundle of eucalyptus tied to a shower arm is one of the most photographed objects on the internet, and one of the most oversold. The pictures are honest: the stems look good against tile, and the bathroom smells faintly of eucalyptus for a while after the water runs. Almost everything printed over those pictures is not.

We sell these bundles. We would rather you bought one knowing what it is, because a bundle bought for the reason on the packet tends to disappoint, and a bundle bought for what it actually does tends to get replaced when it fades.

What is actually happening

Eucalyptus leaves hold their volatile oils in glands in the leaf tissue. Warmth and humidity make those oils more volatile, so more of them reach your nose. That is the whole mechanism. Hot water in a small closed room is a very effective way of warming and humidifying a bundle of leaves, and that is the whole reason the shower works better than a vase in a hallway.

The effect is a scent. It is a real scent, it is noticeable, and in a small bathroom with the door shut and the fan off it is quite strong for the first week or two. A preserved stem holds it longer than a fresh cut one because it was treated to stay supple rather than left to dry brittle. Neither holds it forever. Ours fade over weeks rather than months, and the fade is gradual enough that people usually notice it only when a new bundle goes up.

What the evidence says about the rest

Look at the secondary photographs sold alongside shower eucalyptus almost anywhere, including some of ours, and you will find words printed across the image: promotes sleep, purifies the air, relieves stress, refreshes the mind. Those are health claims. We do not repeat them in writing anywhere on this site, and this section is where we explain why.

The National Center for Complementary and Integrative Health, part of the National Institutes of Health, is direct about the state of the evidence. Aromatherapy is sometimes used for insomnia, it says, but we do not know whether it is helpful, because little rigorous research has been done on the subject. It goes further with a specific study: two contrasting scents, lemon and lavender, tested in people under stress. Lemon had a positive effect on mood. Neither scent affected stress indicators, biochemical markers of immune system changes, or pain control.

That is not the same as saying scent does nothing. A bathroom that smells of eucalyptus is more pleasant than one that smells of nothing, and pleasant is worth paying for. It is a very long way from a claim that a bundle of leaves will purify your air or fix your sleep.

If you use eucalyptus because a doctor suggested it, keep following the doctor. If you have asthma or another respiratory condition, a strongly scented small room is worth approaching carefully rather than enthusiastically, and that is a conversation for whoever treats you, not for a catalogue.

That is not the same as saying scent does nothing. It is a very long way from a claim that a bundle of leaves will purify your air.

The part that matters if you have a cat

This is the section we would move to the top if the internet would let us.

The ASPCA lists eucalyptus as toxic to dogs, cats and horses. The toxic principle is the essential oils, eucalyptol specifically, and the clinical signs it lists are salivation, vomiting, diarrhoea, depression and weakness. Lavender, which we also sell and which turns up in half the shower bundles on the market including two of ours, is on the same list: toxic to dogs, cats and horses, with linalool and linalyl acetate as the toxic principles, and nausea, vomiting and loss of appetite as the signs.

Cats are the practical problem, because cats are the animals that get into showers and chew hanging things. A bundle tied to a shower arm is a hanging thing at exactly the height a curious cat investigates.

Practically: keep the bathroom door shut if a cat lives with you, or hang the bundle where a cat cannot reach it, or choose something from this catalogue that is not on the list. If you suspect an animal has eaten some, the ASPCA Animal Poison Control line is (888) 426-4435, and a consultation fee may apply. Your own vet is the other call.

The one plant we sell that the same reference lists as non-toxic to dogs, cats and horses is rose. If you want dried botanicals in a house with animals, rose petals are the honest recommendation, and they are not the product with the best photographs.

How to hang one so it lasts

Tie it to the arm rather than the head. Water running directly through the leaves washes the oils out faster and leaves the bundle permanently damp, which is how a bundle goes from fragrant to musty in a fortnight. Off to the side, in the steam but out of the stream, is the position.

Hang it upside down. Stems point up, leaves hang down, which is both how the shape reads best and how any water that does land runs off rather than pooling in the bunch.

Give it air between showers. A bathroom that never dries out will grow mould on anything organic, including a bundle of leaves, and a mouldy bundle goes in the bin rather than back on the hook.

Refresh rather than revive. There are tricks for waking a faded bundle up, mostly involving crushing a few leaves or a drop of oil, and they work for an evening. When the colour has gone grey and the scent needs help every time, the bundle has done its work.

What we sell, and in what sizes

Our eucalyptus runs from eleven stems to forty one, at seventeen inches, with the count printed on the label because the count is the only thing that separates one bundle from another. Two of the bundles are mixed with lavender. One is a true blue variety rather than the silver dollar most people picture.

Eleven stems is a small bunch for a small bathroom or a test. Twenty to twenty four is the size in most of the photographs. Forty one is a lot of eucalyptus and it looks it, which is either the point or a surprise depending on the room.

None of them will purify your air. All of them will make the bathroom smell like eucalyptus for a few weeks and look considerably better than a shampoo bottle.

A summary of published guidance from public bodies, not medical or veterinary advice and not a claim about any particular product.

The rest of Oning eucalyptus is on the front page, and the figures behind it are in how we update.