Melatonin for Dogs: Safety, Dosage, and Side Effects

Medications By Ben Team 7 min read May 24, 2021 10 Comments

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melatonin for dogs

Melatonin is a hormone that plays several important roles in the biology of most mammals, including dogs.

Produced in an organ called the pineal gland, tucked deep inside the brain, melatonin is most famous for regulating sleep cycles, but it also influences several other bodily processes.

But while most dogs produce enough melatonin in their body on their own, some may benefit from supplemental dosages, as the important natural hormone appears to help treat a few different health problems.

Fortunately, there are a number of melatonin supplements available to help provide your dog with some relief. But as always, be sure to check with your vet before administering any to your dog.

Melatonin for Dogs: Key Takeaways

  • Melatonin is a naturally occurring hormone produced in the brains of most mammals. People most commonly take melatonin to help promote a proper sleep cycle, and some vets recommend this type of use for animals too.
  • Melatonin also appears to treat a number of other health problems in canines, including clotting disorders, phobias, anxiety, and Alopecia-X.
  • While melatonin is naturally produced by the mammalian brain, it can cause side effects. Accordingly, it is always important to discuss the use of melatonin with your vet before administering any to your dog.

Conditions that Melatonin May Treat in Canines

While often used solely as a sleep aid in humans, is effective for treating a variety of different conditions in dogs.

While It is not FDA-approved for use in canines, and such use is considered “off-label,” many veterinarians recommend using melatonin to treat:

Anxiety – The calming effects of melatonin can help dogs suffering from separation anxiety and similar conditions feel a little calmer. However, it is always important to treat the underlying cause of the anxiety in addition to managing the outward expressions. If you’re battling canine anxiety, you may also want to check out our list of the anxiety medicines for dogs (both OTC solutions and vet-prescribed medications).

Phobias – In addition to more generalized forms of anxiety, melatonin can help dogs deal with fears precipitating from fireworks, thunderstorms, and other common triggers.

Sleep Disturbances – Melatonin helps restore natural canine sleep cycles, which is helpful for dogs with sleep issues who sleep at odd times or dogs who have difficulty sleeping at all. It’s often used to address insomnia connected to age-related cognitive dysfunction witnessed in older dogs, such as sundowners syndrome, which can disrupt normal canine sleeping patterns.

Alopecia-X – Also known as Black Skin Disease, Alopecia-X is an endocrine disorder that causes dogs to experience hair loss and exhibit a darkening of the underlying skin. There is no standard treatment for this condition, but many vets report having success using melatonin.

Clotting Disorders – Melatonin can reduce the speed at which blood clots, so it is occasionally used to treat dogs suffering from some clotting disorders.


Common Side Effects of Melatonin in Dogs

It’s important to note that melatonin does carry a few risks, so you should always consult with a veterinarian before giving it to your dog for any reason. While it is generally thought to be safe, there hasn’t been a great deal of research dedicated to studying melatonin’s effects on dogs.

Many people believe that because it is already produced by the body, it doesn’t matter if they get a little more. But that reasoning is misguided. After all, your body produces adrenaline too, but excessive amounts can easily lead to death.

Some common side effects of dogs’ use of melatonin include:

  • Rapid Heart Rate
  • Headaches
  • Itchiness
  • Vomiting
  • Fertility Problems
  • Upset Stomach
  • Confusion
  • Extreme drowsiness

Always carefully monitor your dog after administering melatonin to watch for an adverse reaction. If your dog exhibits any of these symptoms, contact your veterinarian immediately and follow any advice given.

If the symptoms are not severe, your vet may simply advise you to decrease the dosage, but in serious cases, it may be necessary to go in for an office visit.

Also, be sure to note that despite being pretty safe, melatonin is not appropriate for all dogs. For example, diabetic dogs should not take melatonin, as it can promote insulin resistance.

So, as always, owners should consult their vet before administering this — or any other drugs or supplements — to a dog. 

How Is Melatonin Administered to Dogs?

There are a few different ways you can provide your dog with supplemental melatonin, and each presents a different mixture of pros and cons.

Be sure to follow your vet’s advice when making your choice, if he or she indicated the best form for your dog.

Tablets or Capsules

Most melatonin gracing the shelves of retail establishments and websites like Amazon comes in capsule or tablet form.

This is often the easiest form to administer, and the safest for most owners to use. Some dogs will swallow these caplets voluntarily, but others will only be willing if the pill is put inside a treat or coated with something tasty.

Tablets and capsules come in a variety of strengths, so be sure to select the correct dosage when ordering.


A few companies manufacture a liquid form of melatonin, which is usually packaged in a small vial with an eye dropper that is used to dispense the supplement.

Most such products recommend simply applying the recommended amount to your dog’s food or a treat for convenience’ sake.


While pills are generally the preferred delivery system for melatonin, some veterinarians may recommend that you give melatonin via injection, particularly if your dog is suffering from Alopecia-x.

Although this can be intimidating to many owners, your veterinarian should be able to teach you how to administer injections safely and relatively easily.

Subcutaneous Implant

Usually used to treat Alopecia-X, subcutaneous implants are tiny medical devices, placed beneath your dog’s skin. The implant slowly releases melatonin to keep a steady supply flowing through the bloodstream.

Most implants require replacement every four months or so. Only your veterinarian can insert a subcutaneous implant.

Ingredient Safety

If you plan on giving your dog melatonin, and you have already received your vet’s blessing to do so, be sure to scrutinize the ingredient list on oral tablets or liquids first.

You’ll need to make sure that the supplement does not contain anything harmful to your dog, such as xylitol

Melatonin for Dogs Dosage: How Much to Give a Dog

You should always consult your veterinarian before using melatonin and follow the melatonin dosing regimen he or she provides, but the AKC’s website recommends the following dosages:

Dogs less than 10 pounds: 1 milligram

Dogs between 10 and 25 pounds: 1.5 milligrams

Dogs between 25 and 100 pounds: 3 milligrams

Dogs weighing more than 100 pounds: 3 to 6 milligrams

Keep in mind that you’ll want to be extremely careful when administering melatonin to small dogs, as small differences in the amount of melatonin given can be much more serious than it would be with larger dogs.

Also remember that melatonin should never be given to a pregnant animal or lactating females, nor puppies under 12 weeks of age.

When Should I Administer Melatonin?

Melatonin takes approximately 30 minutes to kick in, so you’ll want to administer it to your dog roughly half-an hour before a thunderstorm or any other stressful event you are looking to help your dog manage.

For sleep assistance, melatonins should be provided in the evening. As a rule of thumb, it’s best to provide the melatonin alongside a meal or snack, since ingesting it on an empty stomach may result in intestinal distress.

Melatonin Products For Dogs

There is no shortage of over-the-counter melatonin products on the market, and there are even versions marketed specifically for dogs. But some are clearly better than others.

Our top pick for most owners will be these 3 milligram K9 Choice Melatonin tablets, which are priced affordably and receive positive endorsements from most owners. If you have a really small dog, you’ll probably want to opt for the 1 milligram tablets instead.

If your dog doesn’t take pills readily, you may want to go with a liquid product. We’d suggest the Ironpower’s Super Concentrate.

As always, make sure you’re shopping for dog-safe supplements that do not contain artificial sweeteners or any other potentially harmful additives.

Melatonin Alternatives For Dogs

If melatonin doesn’t have an effect on your dog, you might also consider trying calming supplement treats or pet CBD oil to help soothe your dog’s stressed out nerves!


Have you ever given your dog melatonin? What condition were you trying to treat? Did it work out well for her? Do you prefer one brand or manufacturer over others?

Tell us all about it in the comments below.

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Written by

Ben Team

Ben is the managing editor for K9 of Mine and has spent most of his adult life working as a wildlife educator and animal-care professional. Ben’s had the chance to work with hundreds of different species, but his favorite animals have always been dogs. He currently lives in Atlanta, GA with his beautiful wife, their Rottie, and their Pyr.


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Mary Jarvis

My 7 year old, 40 pound beagle is in desperate need of getting his nails clipped. They are really long and he doe not like anyone touching his feet. I have taken him to a couple different groomers but they won’t do it. I have been told “ he looked like he was going to bite me, so I won’t do it.” How much melatonin can I safely give him to make he drowsy enough to clip them myself? I gave him 5mg with not side effects, but he still wouldn’t let me clip the nails. I am a senior citizen on a very small and tight income, and the vet wants way too much money. Can you give me an idea how to help my very sweet puppet?
Thank you .

Ben Team

Hey, Mary.
5 milligrams already exceeds the AKC’s guidelines, so we’d hesitate to recommend administering any more than that without first speaking to your vet.
You may, however, want to try to file or grind his nails down instead of clipping them. A lot of dogs tolerate grinding or filing better than clippers, and even those who aren’t thrilled with the idea will learn to accept it over time. Ideally, you’d use a rotary grinder (this one is less than twenty bucks), but you could even use a typical nail file — it just may take a while.
Be sure to give him plenty of treats and praise during the process, take things slow, and let him have breaks as needed. It may take you several days of doing so to make progress, but this approach is often effective for many dogs.
Best of luck!

Susan E Shehan

I decided to try it for anxiety , hyperactivity and not sleeping at night. So I give it to (1mg)him close to bed time.

Barbara King

Can melatonin help kill cancer cells for dogs?

Ben Team

Hey, Barbara.
It looks like a few researchers are trying to examine this possibility, but I can’t find much evidence supporting the contention.
If your pooch is suffering from cancer, we’d recommend asking your vet about it, while embracing the recommended treatment.
Best of luck!

Gen Michael

I give my 25 pound 12 year old min pin. 3mg melatonin pill every 12 hours as part of a protocol for Cushing’s disease. It helps manage effects of too much cortisol. He wakes up at night and is agitated and hungry. The effect wears off too soon I am looking for advice from anyone who has used a melatonin implant in a similar situation. Does it work better?

Gen Michael

I give my 25 pound 12 year old min pin. 3mg melatonin pill every 12 hours as part of a protocol for Cushing’s disease. It helps manage effects of too much cortisol. He wakes up at night and is agitated and hungry. I am looking for advice


Really? How do you know if your dog has a headache?


My Staffy lost all of the hair on his ears, completely bald! My vet researched the condition and decided that Melatonin would be the safest and easiest place to start. He’s a nervous dog, and seems to possibly have a bit of seasonal allergies to boot. We started him at 5mg per day. Amazingly the hair started growing back in only about a week and a half or so.


Thanks for this information


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