Melatonin for Dogs: Uses, Benefits and Side Effects

Photo of author
Updated On

I Love Veterinary blog is reader-supported, and we may earn a commission from products purchased through links on this page, at no additional cost to you. Learn more About Us and our Product Review Process >

Some dogs can sleep through a hurricane, others will react to every noise around them. Some of these might even get anxious and scared when loud noises are sounding around them. 

Studies show that these dogs may benefit from Melatonin for dogs. But, what are the melatonin dosages, are there any side effects, and how can it calm a dog down? Take a read below! 

Scared dog under blanket, Melatonin for Dogs_ Uses, Benefits and Side Effects - I Love Veterinary

What Is Melatonin? 

Melatonin is a naturally occurring hormone present in the brain of both humans and animals. It is produced in the pineal gland – a small pea-sized gland in the brain. Melatonin is most known for regulating our sleep schedules. But, it also – to some degree – regulates our feelings. Especially feelings of stress or anxiety. 

Sometimes the gland doesn’t produce enough melatonin. This is thought to be associated with stress and other distressing emotions. Taking a small dosage of melatonin can possibly help your furry friend to be less stressed and even sleep better. 

What Are the Uses of Melatonin for Dogs? 

So what can Melatonin possibly do for you and your dog? The answer is quite a few things. It generally works as a sedative. Supplementing the natural concentration of Melatonin in the body. This can lower anxiety and calm other unwanted reactions. 

The effectiveness of Melatonin depends on a few factors. These include the general health of your dog, the issue being treated, and it’s severity, as well as the duration of treatment. Melatonin is often given as a supplement to the therapy given for the below conditions. 

Melatonin formula Melatonin for Dogs Uses Benefits and Side Effects I Love Veterinary I Love Veterinary - Blog for Veterinarians, Vet Techs, Students


Estimates say that 20-40% of dogs suffer from some form of separation anxiety. This is, of course, first and foremost distressing and uncomfortable for the dog. But, it can also cause behavioral issues. 

These can sometimes lead to very destructive behavior when left alone. Some owners return home to a destroyed couch or newspapers all over the room. 

Other dogs get significantly stressed and anxious when they hear loud noises. This can be fireworks or thunderstorms. It can be extremely difficult to calm a scared dog down on nights like New Years’ Eve, 4th July, or Bonfire Night.

Melatonin can, in these cases, help some dogs with calming down. Both when they need to be left alone or when you know a thunderstorm is rolling in. It works on the brain to lower the stress,  making your dog more comfortable. As well as keeping your furniture safe from unhealthy coping mechanisms. 

Separation anxiety, Melatonin for Dogs_ Uses, Benefits and Side Effects - I Love Veterinary


Melatonin is often used by humans to help treat insomnia. Just like us, our dogs can suffer from insomnia. It is often stress- or anxiety-related, but sometimes our dogs – like us – can get into a bad habit of waking up several times at night. Some dogs suffer from cognitive dysfunctions that disrupt their sleeping pattern.

Dogs that suffer from insomnia can have other issues during the day due to lack of sleep. Here melatonin may benefit owners to help their dog sleep through the night. In turn, making them happier and healthier during the day. 


Does your dog ever have bald spots for no apparent reason? This may be what is called seasonal flank Alopecia (hair loss). Often it appears on the lower backside near their tail, with nothing specific causing it. 

Some veterinarians will, in these cases, prescribe Melatonin to try. It is not a sure solution, though. It is uncertain whether the hair would grow back anyway, without the Melatonin. It is a harmless solution for most dogs, and some seem to benefit from it. 

Dog with Alopecia, Melatonin for Dogs_ Uses, Benefits and Side Effects - I Love Veterinary


Cushing’s disease happens when the body produces too much of the hormone Cortisol. This can lead to a lot of symptoms in the dogs. Including frequent urination, lethargy (tiredness) and weakness, as well as skin conditions. 

In some dogs, Melatonin can be given to these dogs to lessen the symptoms. Only if the Cushing’s is caused by a tumor on the adrenal or pituitary gland. In these cases, Melatonin will block the uptake of excess cortisol. 

How Is Melatonin Given to Dogs and What Is the Dosage? 

Melatonin for dogs is given orally (through the mouth) as a tablet, capsule, or liquid. 

It can be given with or without food, depending on how you prefer to administer it. However, some dogs can vomit when being given the pill on an empty stomach. In these cases, it should always be given with food. 

The supplement often takes effect quickly, within 1 to 2 hours. Improvement of symptoms, anxiety, and stress should happen shortly thereafter. The effect lasts roughly 8 hours. 

If you miss a dose, do not give your dog a double dose. If it is close to the next dosage, simply skip the missed one. 

The usual dosage for dogs depends on their size. 

  • <5 kg: 1.0 mg 
  • 5 – 15 kg: 1.5 mg
  • >15 kg: 3.0 mg 

It should not be administered more than three times per day. 

Hungry dog, Melatonin for Dogs_ Uses, Benefits and Side Effects - I Love Veterinary

Is Melatonin Safe for My Dog and Are There Any Side Effects? 

Now you know of all the things melatonin can help with, you’re probably wondering whether it is safe and possible to give to your own dog? 

Remember to never give Melatonin to your dogs without first consulting your veterinarian. Generally, Melatonin is a safe supplement. But, there might be individual differences from dog to dog. 

One of the biggest appeals for using Melatonin is that it is natural. Just like vitamins, minerals, and botanical supplements. However, it still has a biological effect, which is why it’s essential to consult a professional first. As a general rule, though, most dogs have few to no adverse effects.  

If your dog ever experiences side effects, report them to your veterinarian. The few that have been registered are

  • Diarrhea 
  • Itching 
  • Tachycardia (faster heart rate) 
  • Confusion

Be very aware that most Melatonin products are sold mostly to humans. Some of these may contain an artificial sweetener called Xylitol. This is toxic for dogs. It is, therefore, important to always read the labels before buying Melatonin for your dog. 

Melatonin should not be given to pregnant or lactating females (female dogs nursing) either. 

Calm dog, Melatonin for Dogs_ Uses, Benefits and Side Effects - I Love Veterinary

Melatonin Drug Interactions 

Melatonin rarely reacts with drugs, but care should be taken when used concurrently with these drugs. 

  • Benzodiazepines (sedative) 
  • Succinylcholine (sedative) 
  • Warfarin (anticoagulation medication) 

Natural supplements can react with each other, also. It is important to inform your veterinarian if your dog receives any other supplements as well. This includes, but isn’t limited to, vitamins, herbal therapies, minerals, and amino acids. 


We all want our furry friends to be happy. This can sometimes be difficult when they’re scared and stressed. Luckily there are options out there, like Melatonin for dogs, that can help alleviate some of the stress. So both you and your dog can happily get through the thunderstorms.

Sharing is caring!

Photo of author


With a veterinary master's degree from the University of Copenhagen in 2023, this accomplished writer's academic journey culminated in a thesis focused on the "Feasibility of using ultrasound of the abdomen for early diagnosis of necrotizing enterocolitis in neonatal pigs." Additionally, their dissertation delved into the intriguing topic of "Mercury accumulation in Greenlandic sleddogs." Beyond her academic achievements, her passion for animal health seamlessly merges with her love for writing. She excels in harmonizing clinical precision with literary expression, crafting articles that resonate with the heartbeat of her veterinary profession.