Pet Pheromone Products

Pet pheromone products are everywhere, sold online and in pet stores, and recommended by vets and magazine writers and bloggers. It's virtually impossible to own a pet and not be bombarded with ads, at some point, for a pet pheromone product. They promise to fix just about every pet behavior problem — being anxious, barking, making a mess inside the house, acting aggressively, scratching furniture — all through the magic of pheromones, those biochemical scents animals use to communicate. One advertisement describes them as "The animal kingdom's secret language... like messages floating in the air." Well, can the solution to all these difficult problems truly be so magically easy? The best way to find out is to point our skeptical eye at pet pheromone products.

A big problem for consumers who buy medical or wellness products for their pets is that the market is even less regulated than is the market for such products made for humans. Unevidenced claims abound, and enforcement of false claims is practically nonexistent. For every pseudoscience-based human health or wellness product, there are scores of knockoffs made for pets — and they're not required to carry the familiar FDA disclaimer (although some do choose to carry it):

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

So arguably, pet products are even more likely to deceive a consumer with an average scientific literacy level into assuming the product is valid. We discussed a lot of these products in episode #641 on alternative veterinary medicine. Acupuncture, homeopathy, chiropractic, worthless supplements, even organic pet food, are all sold to pet owners with implied efficacy. So our task today is to see where pet pheromone products fit into this particular minefield.

Many of these products are sold as diffusers, kind of like a little night light thing that you plug into an outlet and it produces vapor from a small container of the product, for which, of course, you buy refills. Others are sprays or spritzes. But they all promise to contain "calming pheromones" — in not a single advertisement did I ever see these calming chemicals specified by name. But it's easy to find out what are the real things that pheromones do in the animal kingdom:

• They warn of danger, such as signaling a hive of bees to swarm.
• They signal mating readiness.
• They mark territories, often with pheromones in their urine.
• They mark trails to food, as we see among ants.

They do other things too, but in no literature anywhere did I find a mention of "calming pheromones" for dogs and cats. One article I read from 2014 in the journal Annual Review of Physiology reviewed the biological mechanisms of a large number of pheromones. Each one has a chemical composition and a known response for its particular species. The paper contained not a single mention of a "calming pheromone" for dogs or cats, which may explain why none of the advertisers actually say what their active ingredient might be. So far as I can find, there is no such thing as a calming pheromone. Calming one another just isn't a critical life function that groups of animals need to survive and for which a pheromone would be likely to evolve.

Now there's one important semi-exception to this: lactating female dogs do produce a scent called apasine which draws newborn pups to her for nursing. Some researchers have hypothesized that it plays a role in creating a bond between mothers and pups. This is important to be aware of, because the industry has synthesized a version of this and named it Adaptil, and commonly call it DAP (Dog Appeasing Pheromone) which is more than a little aspirational. In essentially all well controlled testing, it has no value at all in calming or appeasing adult dogs in virtually any situation. Its only well-evidenced effect is to help pups nurse. So if you see Adaptil or DAP mentioned in product literature, know that they're promoting something for benefits that have been all but disproven.

As Dr. Brennen McKenzie writes in his 2019 book Placebos for Pets:

As is often the case in veterinary medicine, the market is well ahead of the science, and there is surprisingly little data characterizing the composition, physiologic and behavioral effects, and clinical benefits of dog and cat pheromone products... There is virtually no published peer-reviewed research characterizing the discovery, composition, variability, and physiologic effects of dog and cat pheromones.

So to begin with, bring a healthy dose of skepticism to the table for the claim that a calming pheromone for dogs and cats has ever been definitively identified — and that's shaky ground indeed for these products.

But let's say that these pet product marketers have indeed all made a scientific discovery that has eluded the animal biologist community — or they've all made the discovery but nobody has ventured to publish it. That's still not proof that these products don't work, so let's see what testing has been done to find out for sure.

The study that is by far the most often referenced — as it's about the only out there not commissioned by one of the companies selling these products — is from back in 2010, and was published in the Journal of the American Veterinary Medical Association, "Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs." They found only 14 studies that met their standards for quality, seven about cats and seven about dogs, ranging from 1998 to 2008. Here are the results published in the abstract:

Studies provided insufficient evidence of the effectiveness of feline facial pheromone for management of idiopathic cystitis or calming cats during catheterization and lack of support for reducing stress in hospitalized cats. Only 1 study yielded sufficient evidence that dog-appeasing pheromone reduces fear or anxiety in dogs during training. Six studies yielded insufficient evidence of the effectiveness of dog-appeasing pheromone for treatment of noise phobia (2 reports), travel-related problems, fear or anxiety in the veterinary clinic, and stress- and fear-related behavior in shelter dogs as well as vocalizing and house soiling in recently adopted puppies.

Surprising? Consider that the article also notes, literally in its opening sentence:

Only a few mammalian pheromones have been identified.

Again, underscoring that this notion of the existence of "calming pheromones" for dogs and cats is simply not supported by established facts.

And yet, you'll hear the opposite if you read the marketing materials for these products, which invariably imply they are backed by solid science. Three of the most heavily promoted brands are Feliway, which says it's "backed by over 25 years of feline stress expertise and scientific research"; Thunderease, which says it's been "scientifically studied and verified for over 20 years"; and TheraPet, which says their "unique 2-in-1 pheromones combination" is like "whispering soothing words to your furry friend all day, every day." None of these companies discloses what these elusive pheromones are that they claim to sell, and certainly don't give their chemical compositions.

It's not hard to find justification for such grand claims — you can spend a few minutes on Google and easily find a raft of articles (even journal publications) finding positive effects for these products. You just have to search for the products by name. One veterinary blog broke down a lot of these citations, and found that the company that owns one of these brands sponsored and paid for the research finding positive results. Unsurprisingly, many are among those excluded from the 2010 paper for not meeting methodological quality standards.

Once I started doing the research for this episode, my Facebook feed predictably filled up with ads for them. Not only did it grease some of my work, it provided a treasure trove of glowing testimonials from actual Facebook users — real consumers, not fake website testimonials. And as you can imagine, most are blissfully glowing:

Love this product! It works great for my cats. I can always tell when it's getting low because my spicy cat starts attacking.

It works great for my little devil. Recently, he was getting to be a problem again, and I noticed that the diffuser had run out. I added a refill and he immediately calmed down. He even let me sleep through the night. I think it's a great product.

Our puppy was peeing in the house. Even after just being outside. Plugged two of these in and no more peeing (shhhh, don't jinx it!)

One person said they were giving their dog both Prozac and Trazedone to calm it down, but it was only when they added the pheromone diffuser that the drugs finally worked. Confirmation bias much?

To one Facebook question, the manufacturer replied:

The TheraPet Pheromone diffusers are formulated to help reduce anxiety and stress in pets, including separation anxiety.

Considering that there are no known calming pheromones for dogs or cats, it seems awfully presumptuous of them to claim that they have ability to specifically "formulate" their pheromones to target ailments as specific as separation anxiety — or peeing in the house.

Science also offers us a pretty good explanation for why so many customers believe (or convince themselves) that products that produce no effect are actually doing something. One explanation is that, for the humans who buy them, they act as placebos. You buy it, you turn it on, you believe it's going to do something for your pet, so you get relaxed. And when you're relaxed, your pet seems to you to be more relaxed, and in some cases may key off of your toned-down state and calm themselves. I found a great example of this on the website for one seller of these, amid a list of customer reviews which look very suspiciously fake; for one they all start with some variation of "I was a skeptic until I tried it". It's the old "I was a skeptic, and so I did the least skeptical thing imaginable, which was to buy a product I believed would not work. See what a great skeptic I was?"

This oh-yes-I'm-sure-it's-very-genuine product review (5 stars, like all of them) said:

I expected this to do nothing as I have bought things for my cat before that were just a waste. Yeah it calmed everyone in our house down.

If that actually was a real customer's perception, it's a perfect match for the human placebo effect. This person bought the product (despite their claimed skepticism) and gave it to the cat to calm it down, and then (big surprise) everyone in the house felt relieved that something was being done. Five stars.

Products based on nothing but pure pseudoscience abound throughout the veterinary world, and consumers need to keep their skeptical radar on max power. Pheromone products, on the other hand, only have one foot into the world of pseudoscience. Pheromones are a real thing. Pheromone-based pet care products are scientifically plausible. It's entirely possible that in the future we will be able to synthesize a pheromone that does tend to produce some desired behavior in a dog or cat, but from everything we've been able to learn so far, we're not there yet. The official Skeptoid recommendation on pet pheromone products is to save your money. I give them 0.5 out of 5 Skeptoid Plausibility Points.

By Brian Dunning
Follow @BrianDunning