Can Dogs Take Melatonin?

Written by: Margo Hennet, DVM

January 18, 2022

Melatonin is a naturally-occurring hormone that aids in regulation of sleep-wake cycles, mood, and other functions. It is primarily produced by the pineal gland in the brain, where its production schedule is linked to the time of day; i.e., more is produced at night to help with sleep. While many people take it as a supplement to assist with various sleep-related issues, did you know melatonin has a wide range of potential uses in dogs?

Before we dive into how melatonin can benefit our furry friends, remember that if there is a problem you are trying to fix, it is best to first investigate and officially diagnose the issue with a veterinarian! There are many conditions out there that can look pretty similar, and many medications that don’t play well together. Be safe, and ask your vet before starting a new medication or nutraceutical!

beagle looking at the camera

Benefits Of Melatonin For Dogs

We know why humans take melatonin, but how can it help dogs?


In humans, supplementing melatonin has been shown to help regulate circadian rhythms in the blind, reduce the time it takes to fall asleep, and relieve jet-lag symptoms. It may also help with insomnia and other sleep disorders1, but the research is still out on that.

In dogs, melatonin is often used in patients with canine cognitive dysfunction (a bit like dementia for our senior dogs) to help manage nighttime waking, pacing, and anxiety2 associated with this condition.


Research has shown that melatonin supplements can have a sedative effect when given to dogs. This property can help with separation anxiety, stress caused by loud noises such as fireworks or thunderstorms, and as a way to calm nerves before an operation or other procedure3.

In many instances, melatonin is part of a multi-medication therapy, meaning that it’s used in combination with other medications to achieve a desired level of calm4—think basking in the sun on a warm spring day type zen.

funny looking french bulldog

Hair Loss

Another well-established use for melatonin in canine medicine is as a therapy for abnormal hair loss, also known as “alopecia.” Melatonin can act as a hair-cycle inducer to help hair grow5, and therefore can be helpful for conditions such as Alopecia X, Seasonal Flank Alopecia, and Post–clipping Alopecia. It doesn’t always work to the same degree in every dog, however6.

Immune-Mediated Diseases

There may be a role for melatonin in the treatment of immune-mediated disease in dogs—meaning those conditions that occur when immune cells overreact and attack the body’s own tissues—such as immune-mediated thrombocytopenia (low blood platelet count; the cells that help blood clot) and immune-mediated hemolytic anemia (the destruction of red blood cells at a rate faster than they can be made). Melatonin’s benefit in these scenarios has not been fully confirmed by research studies yet.

Hormonal Influence

A hormone itself, melatonin interacts with or influences the effect of sex hormones, cortisol (the stress hormone), and insulin, which means extra melatonin must be used with care for any dogs with endocrine (hormone-related) disease, dogs on steroid medications, or any dogs intended for breeding7.

fluffy dog laying on its back


Melatonin may help prevent some seizures in dogs, and can in some cases be used with anticonvulsant therapy3, designed to control seizures with the fewest medications. Melatonin’s role in preventing seizures is still not completely clear, however, as some studies suggest it may not be as useful in dogs as it is in humans8.

Antioxidant Effects

A recent study shows that melatonin seems to positively impact oxidative stress levels (an imbalance between antioxidants and pro-oxident factors, which can lead to cell and DNA damage) in dogs suffering from certain heart diseases9. Since oxidative stress can contribute to the progression of heart disease, this may be good news for our frosty-faced senior dogs.

There are a number of other melatonin-induced effects that have been demonstrated in humans and other animals, but not yet investigated for dogs. As researchers learn more and explore the benefits of melatonin supplementation in dogs, we might see its use increase!

If you and your vet decide it’s a good treatment option for, say, anxiety, then your pup won’t have to count the days down to the Fourth of July with trepidation, or even just the few minutes when you step outside to grab something that you forgot in your car.

two puppies sleeping on a bed next to each other

Important: Melatonin supplements for dogs have not been approved by the FDA, and as with all medications, side effects are possible. Chat with your vet if you think you may want to try it for your dog.

Margo Hennet, DVM, cVMA, and veterinarian at BARK is a canine nutrition, health, & wellness connoisseur. She has a combined 10 years of experience in clinical medicine, research, and education—that’s 70 dog years of know-how—and graduated from Colorado State University as a Doctor of Veterinary Medicine. She completed specialized training in internal medicine prior to working as a general practitioner in Colorado, has authored peer-reviewed publications and textbook chapters, holds certification in veterinary medical acupuncture, and is a member of the American Academy of Veterinary Nutrition and American Veterinary Medical Association.


1 “Melatonin.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 3 Mar. 2021, 

2 O’Dell CB. Alternative treatments in hospice and palliative care. In: International Association of Animal Hospice and Palliative Care 2014 Proceedings Online. Franklin, IN, USA; 2014. Available at: Accessed January 15, 2022. 

3 E;, Niggemann JR;Tichy A;Eberspächer-Schweda MC;Eberspächer-Schweda. “Preoperative Calming Effect of Melatonin and Its Influence on Propofol Dose for Anesthesia Induction in Healthy Dogs.” Veterinary Anaesthesia and Analgesia, U.S. National Library of Medicine, 

4 Landsberg G. Treating canine and feline anxiety: drug therapy and pheromones. In: British Small Animal Veterinary Association Congress 2008 Proceedings Online. Thornhill, ON, Canada; 2008. Available at: Accessed January 15, 2022.

5 Fischer, TW, Slominski A, Tobin DJ, Paus R. Melatonin and the hair follicle. J Pineal Res 2008; 44(1):1-15. 

6 Frank LA, Hnilica KA, Oliver JW. Adrenal steroid hormone concentrations in dogs with hair cycle arrest (Alopecia X) before and during treatment with melatonin and mitotane. Vet Dermatol 2004;15:278-284. 

7 Ashley PF, Frank LA, Schmeitzel LP, Bailey EM, Oliver JW. Effect of oral melatonin administration on sex hormone, prolactin, and thyroid hormone concentrations in adult dogs. J Am Vet Med Assoc 1999; 215(8):1111-5.

8 Thomovsky SA, Chen AV, Deavila DM, Kiszonas AM. Serum melatonin values in normal dogs and dogs with seizures. J Am Anim Hosp Assoc 2019; 55(2): 78-82. 

9 Pongkan W, Piamsiri C, Dechvongya S, Punyapornwitthaya V, Boonyapakorn C. Short-term melatonin supplementation decreases oxidative stress but does not affect left ventricular structure and function in myxomatous mitral valve degenerative dogs. BMC Vet Res 2022; 18(1):24. 

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Written by: Margo Hennet, DVM

January 18, 2022

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