My Dog Ate Melatonin

Melatonin is a hormone that is already present in our bodies, both in humans and dogs. It can also be taken as a supplement and it comes in tablets, gummies, and liquids.

A high dosage or amount of melatonin ingested will be harmful to your pet, especially if it contains xylitol. Otherwise, melatonin is mostly harmless for dogs.

What should I do if I discover that my dog has eaten melatonin?

Before phoning your local veterinarian or pet poison helpline, remove any uneaten melatonin so that your dog and other animals in the house cannot eat any more.

Don’t try to make your dog vomit without the consent or instruction of your veterinarian. Inducing vomiting can be dangerous if your dog is drowsy or unconscious and may result in them choking or inhaling their own vomit.

Try to determine the amount of melatonin that your dog has eaten. The label on the bottle should state the amount of melatonin contained per tablet, chew, or capsule. Multiply this by the amount of melatonin missing to get an estimate of the dose that your dog has eaten. The more information you have, the better the advice that your veterinarian or poison control helpline operator will be able to give you. Don’t worry if it’s not possible to do this.

Try to work out the time at which your dog ate melatonin. Take note if your pet is currently showing any signs of an overdose. Symptoms start to show roughly 20 to 30 minutes after ingestion.

Check the label on the melatonin bottle and determine if there are any other ingredients included such as xylitol. As previously mentioned, many human grade melatonin products contain this artificial sweetener. If your dog ingests xylitol, this is a true medical emergency, and your dog should be rushed to the closest veterinary clinic as soon as possible.

Call your local veterinarian or pet poison helpline. Depending on the dose of melatonin that your dog ate as well as whether it contains any harmful additives, you may be advised to take your dog to your local veterinarian. If it has been less than two hours since ingestion, your vet may induce vomiting. Your vet may also want to hospitalize your dog for observation and for treatment of any side effects that may arise from the melatonin overdose.

Melatonin is a hormone produced primarily by the pineal gland. This naturally occurring hormone helps regulate the sleep-wake cycle in both humans and animals.

Melatonin levels rise in the evening in response to darkness. At nighttime, melatonin levels are up to ten times higher than during the day. The increase in melatonin brings about a feeling of calm and signals to the body that it is time for sleep.

Melatonin also influences reproductive cycles, especially in animals that are seasonal breeders.

Possible Symptoms of a Dog That Has Eaten Melatonin

Plain melatonin containing no sweeteners is generally not toxic to dogs. However, depending on how much was ingested and the dog’s general health, some side effects may occur.

It is important to keep in mind that melatonin commonly causes drowsiness. If your dog ingests a small amount of melatonin and becomes sleepy afterward but exhibits no other symptoms, there is likely no cause for concern. Even so, it is a good idea to keep an eye on a dog who has eaten a supplement that isn’t intended for them.

Symptoms other than sleepiness that a dog might experience after eating a melatonin supplement include nausea, vomiting, diarrhea, increased heart rate or blood pressure, lack of coordination or confusion, weight gain, or changes in fertility (in dogs who aren’t spayed or neutered).

Dogs who are more likely to experience complications from ingesting melatonin include those with liver or kidney problems, those who are diabetic, and those who are already on medications, including meds used for the treatment of anxiety in dogs.

Because of its effect on the reproductive cycle and fertility hormones, care should also be taken to keep melatonin away from pregnant or nursing dogs and very young puppies.

Generally, a single dose or pill is unlikely to cause a serious reaction, with the exception of melatonin that includes xylitol—more on that below.

What To Do If Your Dog Ingests Melatonin

The first thing to do if your dog ingested your melatonin is to figure out how much melatonin the dog ate, if possible. Because melatonin can be bought in many forms including pills, gummies, and liquids, determining how much your dog ate may not always be very straightforward.

In a scenario in which you cannot figure out how much melatonin your dog ate or whether your dog is exhibiting signs of poisoning, you have the option to either seek advice from your veterinarian or a pet poison control helpline—such as the ASPCA Animal Poison Control Center at (888)426-4435—or to wait and see how your dog reacts. Because most canine melatonin supplements do not exceed 6 mg, though, it is a good idea to seek help if the dose was larger than that.

If you know for a fact that your dog ate a small dose of melatonin (under 6 mg) and your dog is otherwise healthy, waiting may be appropriate; however, if there is a possibility that your dog ate a lot of melatonin, it would be a better idea to take your pup to the vet or call a helpline.

My Dog Ate Melatonin


What if a dog eats melatonin?

Your pet may have a slightly upset stomach, for example, and also show signs of sleepiness. Significant overdoses can produce much more serious symptoms and require an urgent response. Signs to keep an eye out for include vomiting and diarrhea, loss of coordination, high blood pressure, and even seizures.

How much melatonin can hurt a dog?

According to Plumb’s Veterinary Drug Handbook, the appropriate dose for dogs with sleeping disorders is between 3 and 6 milligrams12. If your dog is suffering from anxiety disorders, then Plumb’s Handbook indicates 0.1 milligram of melatonin per kilogram of body weight.

Can dogs overdose on dog melatonin?

Yes, a dog can overdose on melatonin if it ate too much. Symptoms can start with vomiting or diarrhea and turn into incoordination, fast heart rate, high blood pressure, and seizures.

Is 5 mg of melatonin too much for a dog?

Dog owners that supplement with melatonin report normal hair growth, normal energy levels, and normal appetite and urination in their dogs. Veterinarians recommend giving dogs over 30lbs 5mg melatonin (1 tablet) every 12 hours. For smaller dogs visit our Amazon storefront for other dosages and flavors.