Melatonin for Dogs [Complete Guide]

Melatonin is a neurohormone that all of us — including dogs — naturally produce. Supplementation has long been a way of improving sleep disorders in humans. But what about Melatonin for dogs?

melatonin for dogs
Is Melatonin good for dogs?

As time goes on, we’re also beginning to see how melatonin can help dogs experiencing anxiety, sleeplessness, and even hair loss. 

In this guide, you’ll learn everything you need to know about how to spot if your dog might need a melatonin supplement, how to dose it, and things to know before you begin. 

Is Melatonin Safe For Dogs? 

Melatonin is safe for dogs if the proper dosage is used and the medication is administered under the guidance of a veterinarian. This is because melatonin can cause some side effects, especially in dogs with certain health conditions or who take other medications. 

It’s important to note that the Food and Drug Administration does not regulate supplements like melatonin for humans or animals. That means it falls on you to check that the supplement you use is dosed properly and does not contain ingredients that are toxic to dogs, such as xylitol (found in artificially sweet foods like some jelly beans or almond milk). 

Watch your dog for signs of lethargy, extreme tiredness, tachycardia, or stomach problems.

puppy at the vet with owners one adult one child
A cute puppy enjoying a Vet visit

Why Might a Dog Need Melatonin? 

In humans, melatonin is usually used to help regulate sleep disorders, including insomnia. While it has the same application for dogs, it may also be used for anxiety, hair loss, Cushing’s Disease, or as a supplement while going through chemotherapy. 

Here are the top reasons that dogs might need a melatonin supplement:

Separation anxietyMany dogs have separation anxiety, meaning that they get extremely nervous when their owner leaves the house. Dogs with separation anxiety may act out by toileting throughout the house, chewing furniture, barking excessively, or howling. Melatonin supplementation often helps. In a case like this, owners would only need to give their dog a dose when they were leaving the house. 

Noise-related anxiety – Many dogs become panicked during thunderstorms or if there are other loud noises like fireworks. If your dog’s anxiety is extreme during these events, you may want to consider giving them a dose of melatonin. 

Generalized anxiety – Some dogs are naturally very nervous and may get especially panicked around new people, unfamiliar places, or unknown experiences. This may also happen to dogs with a history of trauma, abuse, or neglect. If your dog is generally very nervous, they may benefit from a daily melatonin supplement. 

Hyperactivity – Seriously hyperactive dogs may benefit from the sedative properties of melatonin. This is best recommended if your dog is so hyper that they tend to jump on people, nip, chew furniture, or break things around the house. It has similar effects in dogs with epilepsy.

Sleep disruptions – Most dogs sleep well, but can have disrupted sleep patterns as they age. In particular, elderly dogs may have Canine Cognitive Dysfunction, which is similar to Alzheimer’s. This can make it hard to sleep or cause restless sleep. Melatonin can make it easier for your senior dog to fall and stay asleep.

Blind dogs may also have trouble sleeping. That is because they, like blind humans, have difficulty recognizing when it is day or night, which can disrupt their natural circadian rhythm.

Hair loss – For reasons that scientists don’t quite understand, melatonin supplementation seems to help dogs with chronic hair loss, also called canine alopecia. If your dog is losing its fur, your vet may prescribe a supplement.

Chemotherapy – Dogs who are undergoing chemotherapy can lose weight, as the treatment causes nausea and suppresses appetite. Some evidence suggests that a melatonin supplement can help reduce these side effects and promote weight gain. However, you should always check with your vet before introducing melatonin to a dog undergoing chemotherapy.

Cushing’s Disease – Some studies suggest that a melatonin supplement could help dogs with Cushing’s Disease. This is caused by the body producing too much cortisol, a hormone. Melatonin plays a role in balancing hormone levels, including cortisol. 

How To Spot When Your Dog Needs Melatonin 

Some cases are easy to spot, like if your dog is losing hair or seems like they’re not sleeping well. However, it may be difficult to spot if your dog is feeling excessively anxious. 

Top signs of anxiety in dogs include:

Toileting throughout the house – Many animals show signs of anxiety by having accidents around the house. If your dog has suddenly started urinating or defecating on the floor rather than asking to go outside, it might be a sign that they’re feeling agitated. 

Destructive behavior – Dogs often show anxiety by engaging in destructive behavior. This might be directed at objects around the house. They may chew furniture, rip up pillows and blankets, scratch walls, and more. It may also be self-directed, which is more serious. Dogs with anxiety can engage in self-harming behaviors, like excessive grooming, biting, chewing, or ripping their fur out.

Excessive barking or howling – This is especially true in dogs with separation anxiety, who may bark for hours while their owner is away.

How Quickly Will Melatonin Start To Help My Dog?

You will notice the melatonin starting to take effect quickly. Your dog will probably start showing signs after an hour or two, but it may be as fast as 15 minutes. As you continue to dose, the symptoms should continue to improve. 

sleeping cockapoo puppy
Audrey – Photo by Tim Collins /CC BY

Can You Give Your Dog Melatonin For Humans? 

It’s generally not a good idea to give your dog melatonin products formulated for humans. There are a few reasons for this. First, the dosages are significantly higher. Adult humans can take as much as 10 mg of melatonin in a single dose, while even the largest dogs should take no more than six. Trying to cut up a pill to the right size doesn’t guarantee accuracy, and you could hurt your dog trying to do so. 

Secondly, supplements made for humans often have additives that are not safe for dogs, such as xylitol, a sweetener that can cause seizures, liver failure, and even death. 

How To Dose Melatonin For Dogs 

Don’t try to dose melatonin without the guidance of your vet. Remember that your dog’s needs are unique and may be affected by their specific health conditions or medications. 

Your vet might advise that you start with a lower dose and then increase it if your dog’s symptoms haven’t improved. This can also avoid making your dog lethargic or groggy. 

The general way of dosing melatonin is by weight.

  • Dogs under 10 lbs – 1 mg
  • 10-25 lbs – 1.5 mg
  • 26-100 lbs – 3 mg
  • 100+ lbs – 3-6 mg

Effects usually last eight hours. If you need to give your dog more when they stop responding to the medication, that’s fine. But don’t give melatonin more than three times a day.

How To Get Your Dog To Take Melatonin 

Melatonin for pets is taken orally, as a pill, capsule, or liquid. You can give it either with or without food, but note that it might cause vomiting if taken on an empty stomach. If you prefer, you can give it to your dog with a treat or in their regular food. 

Administering melatonin as a liquid medication is often easiest, as you can simply open your dog’s mouth and gently squirt it with a syringe. Aim for the back of the cheek rather than the throat to help them avoid choking or gagging.

Usually, the easiest way to give your dog a pill is to include it in a treat. Many people put pills in with soft dog food or a small bit of human food, such as cheese or peanut butter. Make sure to watch and see if your dog swallows the pill, as some pets can be sneaky. You may also be able to find chewable melatonin supplements made especially for dogs.

dealing with a hyper puppy is tricky
Older dogs and puppies are both susceptible to hyper night time behavior

Are There Any Side Effects?

As with any medication, even natural supplements, you will need to weigh the risks and benefits before starting your dog on a melatonin regimen. Make sure to talk to your vet before giving your dog melatonin so that they help you provide it as safely as possible. 

Don’t ever give your dog melatonin without talking to your veterinarian. That’s because it can exacerbate certain medical conditions or interact badly with other medications. If your dog is pregnant, she should not be put on a melatonin regimen. Never give melatonin to a dog with diabetes, as some evidence suggests that it could increase insulin resistance.

Side effects in dogs don’t happen often. But they are always possible. Your dog might experience stomach upset, a racing heart, irritability or confusion, or itchy skin.

If you notice your dog developing any of these symptoms, discontinue the melatonin and contact your vet as soon as possible. 


If your dog has trouble sleeping or is feeling anxious, melatonin might be a good first step. However, you should never start a melatonin regimen without the guidance of your vet. They can help you determine the right dosage for your dog and if it’s safe for them with their unique medical needs.