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Has your cat eaten some melatonin? Are you worried the melatonin will make your cat sick? If so, then you’ve come to the right place. We understand it can be scary when your kitty eats something she shouldn’t.
In this article, we’ll take a look at what melatonin is and whether or not it can make your cat sick. Let’s get started!
What is Melatonin?
Melatonin is a type of hormone, which is used as a natural supplement to treat sleep problems in humans, particularly in older patients. However, it does have a wide range of other too, including:
- Acting as an antioxidant, which can be helpful in some cancer cases
- Could reduce symptoms of seasonal depression
- Promotes eye health
- May provide relief from acid reflux
- Regulates the immune system
What about melatonin and cats? Can melatonin make cats sick?
Melatonin & Cats
The good news is that melatonin is also used to treat certain health issues in cats and dogs. It’s sometimes used to treat sleep and anxiety problems, as well as some conditions affecting the skin. . So, melatonin is generally considered reasonably safe, including in cats. However, if too much melatonin is ingested then some side effects may be seen.

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Ask a Vet Live NowSymptoms of Melatonin Overdose & Adverse Reactions in Cats
- Studies are limited in the side effects on pets and seem uncommon, but these symptoms might be seen: Sleepiness (more than usual)
- Vomiting
- Diarrhea
- May interact with other sedative medications
- Weight and fertility changes if the medication is taken over a period of time
If your cat has eaten melatonin, she will probably be OK. However, it’s still a good idea to call the vet and let them know what has happened. It can be helpful to tell your vet how much your cat has eaten if possible, along with the dosage contained in one pill (check the packet).
The vet may advise letting your cat sleep off the melatonin. It usually leaves the system in about 24 hours. However, it’s still important to monitor your cat for any other symptoms that may arise during that time.
Always call the vet if you’re worried and/or if your cat has developed new symptoms. Your vet will have the best information on what to do next to help your kitty.
Connect with a verified veterinarian in minutes. Licensed vets are available 24/7 to answer your questions. No need to worry about your furry family member.

Rebecca MacMillan, BVetMed BSAVA PGCertSAM MRCVS
This article has been reviewed and approved by an independent Veterinarian: Rebecca is a companion animal vet who has always had a passion for writing and client communication. Since her graduation from the Royal Veterinary college in 2009 she has gained a wealth of experience in first opinion small animal practice, in both clinical and managerial roles. She currently works in the South West and deals with a variety of routine and emergency appointments, but particularly enjoys medicine cases. Outside of work and writing, she enjoys spending time with her family, including her bouncy flat coated retriever George!
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