Do cat calming diffusers work? Feliway Classic vs Friends compared

How a cat calming diffuser works

Cats make several kinds of pheromone. These are scent chemicals that carry messages between animals of the same species. The one copied in Feliway Classic comes from a cat's face. Cats spread it when they rub their cheeks on furniture, doorways and people, and it marks those places as familiar.

Feliway Friends copies a different signal. A mother cat releases it from around her mammary glands after giving birth, and it helps her kittens bond with each other. The product uses a copy of that signal to help adult cats who share a home get along.

The diffuser itself is a small heater. You screw a vial of liquid onto the unit and plug it into the wall. The unit warms the liquid, and the vapour rises into the room in a column of warm air. That's why the unit feels warm to the touch, and why it needs clear space above it. One refill lasts up to 30 days, and one diffuser covers up to 70 square metres.

These signals are specific to cats. People and dogs can't detect them, so the room won't smell any different to you or to a dog in the house. Because you can't smell it, you can't tell from the room whether the diffuser is doing anything.

What the research shows

The evidence is mixed. A 2010 systematic review in the Journal of the American Veterinary Medical Association looked at 14 studies of pheromone products in cats and dogs. It found that 11 of them gave insufficient evidence that the products worked, and one found no support at all. The one study with clear support was in dogs, where a dog pheromone reduced fear during training. For cats, there was too little evidence on bladder inflammation (cystitis) and on calming cats during a vet procedure. There was no support for reducing stress in cats staying in hospital.

That review is now more than 15 years old, and Feliway Friends came along later. In a 2019 pilot trial of Feliway Friends, 45 homes with two to five cats were given either a Feliway Friends diffuser or a placebo diffuser for four weeks. Every home had cats that had been fighting for at least two weeks. Aggression scores fell in both groups over the study, and the results favoured the pheromone group.

Two details matter when you read that result. The trial was small, and it was funded by Ceva, the company that makes Feliway. Every home was also coached on handling fights without punishment, alongside the diffuser. So the study suggests Feliway Friends is promising for cats that fight, as one part of a wider plan.

Our view is that a diffuser is worth trying for the right problem, as long as your expectations are modest. Try it for a set period, watch for change, and keep working on the causes at the same time. If you'd rather start with something your cat eats or wears, we compare calming treats, sprays and collars as well.

Feliway Classic or Feliway Friends?

The two diffusers look almost the same, but they aren't interchangeable. The plain FELIWAY Diffuser is usually called Feliway Classic, and it uses the facial pheromone copy. It's aimed at a cat showing signs of stress. That includes spraying urine, scratching walls or furniture, hiding, and reacting badly to a change such as a move, new furniture, a new baby or new people in the house.

Feliway Friends uses the mother-cat signal. It's designed for homes with two or more cats that show tension, such as fighting, chasing, one cat blocking another's way, or staring. It isn't made for a single cat. And if your cats are fighting and one is also spraying or scratching indoors, Classic is the one aimed at those signs.

You can run both at once. That makes sense in a multi-cat home where the cats clash and one of them also shows stress on its own, such as hiding or spraying. Here's how the two compare at a glance.

Where to plug it in

Placement makes a real difference, because the vapour needs room to rise and spread. Choose the room where your cat spends the most time. If your cats each prefer a different room, you may need a diffuser in each one. In a large or multi-level house, plan on using more than one.

1. Pick an open wall socket

   Use a socket with at least 1.2 metres of clear space above it. Don't plug it in under a shelf or table, behind a door or curtain, or behind furniture. If the vapour can't rise, it can settle and leave an oily mark on the wall.

2. Keep it away from moving air

   Air-con vents, open windows and strong draughts make the refill run out faster than 30 days. That matters in an Australian summer, when windows stay open or the air-con runs for much of the day.

3. Plug it straight into the wall

   Don't use a power board, an extension lead or a travel adapter. The FELIWAY Diffuser plug meets Australian and New Zealand electrical safety standards. A unit made for another country's power supply should never be used with an adapter or voltage converter.

4. Leave it on and keep it fresh

   Keep the diffuser switched on day and night. Swap the refill every four weeks, even if a little liquid is left. Replace the plug-in unit itself after six months of continuous use.

If you keep birds or fish, plug the diffuser into a different room from them. Parrots and budgies have sensitive airways, so the safe choice is to keep any diffuser out of the room where they live. The same precaution applies to an aquarium. If your cat spends most of its time in the aquarium room, use the socket furthest from the tank.

What a diffuser can't fix

A diffuser is only meant for stress. If the real cause is something else, it won't help, and waiting to see whether it works can delay finding out what's wrong. The RSPCA's guide to pain in cats lists hiding, aggression and changes in eating, grooming or litter tray use as signs of pain that need a prompt vet visit. Over-grooming is a good example. In a 2006 study of 21 cats thought to be over-grooming from stress, 16 turned out to have a medical cause of itching. See your vet to rule out a medical cause before you try a diffuser.

Your home setup matters just as much. A cat without a clean litter tray will keep going somewhere else. A cat without a sturdy scratching post it likes will keep using the couch. Feliway Friends also won't settle cats that have to share one food bowl and one litter tray, because they'll keep competing for them.

For homes with more than one cat, the RSPCA's guide to introducing a new cat says tension most often comes from cats not having their own resources. Each cat needs its own food, water, litter tray, scratching spot, resting place and hiding place. Set these up in separate spots, out of sight of the other cats.

A diffuser also isn't the answer when a cat is aggressive towards people. That needs a vet or a qualified animal behaviourist, who can work out what's driving it.

Using a diffuser for a new cat, a move or a trip

Planned changes are where a diffuser is easiest to use well, because you can start it early. The same RSPCA guide suggests switching on pheromone diffusers 24–48 hours before a new cat comes home. Keep them running through the introduction, both in the main living area and in the room where the new cat stays first.

Feliway Classic is the one aimed at planned changes, including moving house, renovating and a new pet arriving. If the cats start to clash once they're living together, Feliway Friends is the one made for that. Some households end up running one of each for a while.

For a move, set up one quiet room with a litter tray, food, water, a bed and a scratching post before your cat arrives. The RSPCA's advice on moving with a cat is to keep your cat in that one room for a couple of days, then let it explore the rest of the house slowly. A diffuser in that room means it's working where your cat spends those first days.

A diffuser at home can't help in the car or at the vet. For trips, there's a FELIWAY Spray that uses the same facial pheromone copy as Classic. Spray it into the carrier at least 15 minutes before your cat goes in. Never spray it onto your cat, or into the carrier while your cat is inside. Keep it off scratching posts, because the spray can put a cat off using them.