Mental Health Benefits of Melatonin for Dogs

If Independence Day and New Year’s Eve fireworks drive your pets crazy or if your pets get anxious when they travel or experience new surroundings, people or pets, you may have considered the use of melatonin for their relief.  

What Is Melatonin? 

Melatonin is a hormone produced, primarily, in the pineal gland of mammals.  Melatonin tells cells and systems throughout the body whether it is dark or light outside and, based on the length of those dark-light cycles, what season of the year it is.  In people and other mammals, melatonin levels are high during the darkness of night and low during daytime hours.  Thus, for example, in mammals that are not nocturnal (diurnal), high melatonin levels prepare the body and its various systems for and induce sleep.  (It has the opposite effect in nocturnal animals.)  But, as discussed below, melatonin is about much more than just sleep.   

Why Is Melatonin Prescribed for Dogs? 

Melatonin is prescribed in both human and veterinary medicine. Humans have been taking melatonin for a long time, but more recently, pet owners and veterinarians have begun using melatonin for dogs and cats.  

In other posts we have discussed the many benefits of melatonin to your pet’s physical well-being and sleep, including for treatment of eye conditions; central nervous system disorders such as memory loss, symptoms of Alzheimer’s and Parkinson’s disease and seasonal depression; and coronary disease and high blood pressure.  Readers of this blog are also familiar with melatonin’s critical role in the treatment of Cushing’s syndrome and its function as a powerful anti-oxidant.  In this post, we highlight some of the benefits of melatonin for your pet’s mental health and well-being. 

Every year around this time we get calls and emails from pet owners asking if there is anything they can do about their pet’s anxiety to fireworks displays.  We also regularly get questions about generalized anxiety issues and specific situations like when the pet travels or experiences other unfamiliar situations such as a pet sitter, a trip to the vet, a boarding situation, a new member of the family, thunderstorms or loud construction work nearby.  Melatonin may help calm the pet in each of these situations.  Your veterinarian may recommend melatonin either by itself or in addition to a non-drug treatment or behavioral therapy to help boost the recovery process. 

What benefits can melatonin provide? 


Melatonin promotes calmness in dogs and cats by reducing stress. Several studies have shown that melatonin effectively treats a range of types of anxiety in dogs and cats.  

Too much dopamine may also promote anxiety in dogs and cats. A study conducted by the British Small Animal Veterinary Congress suggests that melatonin suppresses or inhibits dopamine. Thus, melatonin may also calm your pet by reducing dopamine concentrations. 

Mood booster and overall health 

Melatonin is also a mood booster.  It has been shown to stimulate the secretion of serotonin, “the happiness hormone.” Another study suggests that melatonin may be effective for treating depression and for relieving different types of stress. 


As we get older, humans, dogs and cats alike produce less and less melatonin.  Melatonin supplements are useful to help your older dog or cat get their sleep pattern back. Induction of sleep is essential for senior dogs who have reduced cognitive abilities or blind dogs who cannot see at night. 

Can I Give My Dog Melatonin, and Is It Safe? 

Most pet owners are aware of the wonders melatonin can perform. However, they wonder if it is safe to give melatonin to their dog or cat? The answer is yes; melatonin itself is safe to give to dogs and cats.   

The most common side effects that your dog or cat may experience are fatigue, drowsiness, digestive upset, and sometimes increased heart rate.  However, some melatonin supplements (including, unfortunately, some of those marketed specifically for dogs and cats) may contain “inactive” or “other” ingredients that can be harmful to your pet.  For example, some contain xylitol, which can be extremely harmful to your dog, even in small doses.  Others may contain ingredients that may worsen another condition that your pet has.  For example, pets that suffer from insulin dysregulation (including most Cushing’s pets) should avoid supplements that contain sugars and starches such as rice flour or other flours, and dogs on a vegetarian diet will want to avoid gelatin capsules. 

One other caution is that in this post we are talking about dogs and cats.  Although the hormone itself is present in nearly every living thing (plants included!), melatonin’s specific functions across species can vary dramatically.  Your veterinarian can tell you if it is the right choice for your animal.  

Final thoughts 

Melatonin is an excellent supplement to help your dog and cat fight their sleep, cognitive, stress, anxiety and many other problems.  However, you should carefully evaluate what other ingredients are added to the melatonin and select a formulation that won’t harm your animal.  As with any supplement, you should discuss with your veterinarian if melatonin is right for your pet.