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Can I give my cat human L-lysine pills? What's the right dosage?

Updated on September 23rd, 2025

Pet's info: Cat | Persian | Female | unspayed | 3 years and 10 months old | 8 lbs

Can I use human l-lysine pills for cats? How much is the dosage for every kg? Thanks

3 Answers

Most Helpful Answer

Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on March 1st, 2017

Yes you can use human grade lysine for cats, but getting a cat specific one is easier in terms of getting Nabat to take them because they are flavored. If you use a human grade one, you can cut a 500mg pill in half and mix it in with her food twice a day. For the cat ones, Enisyl and Viralys are both good brands, and can be purchased over the counter without a prescription - just follow the dosing instructions on the label based on your cat's weight.

16Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Jennifer Ladd, DVM
Veterinarian
Published on April 9th, 2017
I would also like to add that sourcing is a big issue for supplements. Apart from the palatabity, some companies are better than others. If you choose this route, make sure you speak with someone in a supplement specialty store about reputation. Since there is no governing body for supplements, contaminants are possible.
1Pet Parents found this answer helpful
Answered By Dr. Strydom, DVM
Veterinarian
Published on December 9th, 2017
No, use only lysine that is made for cats. It is specially formulated so that cats can absorb it and it is in the correct dosage so there is no possibility for overdosing. It comes in many forms: gel, treats/chews, powder, etc. So just use whichever one you think Muffin will eat.

https://www.google.com/search?q=lysine+for+cats&source=lnms&tbm=shop&sa=X&ved=0ahUKEwjcye3Gov7XAhXp6IMKHRLXCnUQ_AUICigB&biw=1301&bih=619

As for dosing, just follow the dosing on the product that you purchase. The dosing varies depending on what you are using it for. If you are using it as an immune booster/preventive then the dose will be lower than if you are using it to treat an outbreak of herpes virus (for example).

Hope this helps. Best wishes.
1Pet Parents found this answer helpful

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Food & Nutrition

Is lysine safe for cats on meds, kidney diet, and appetite stimulants?

I would recommend checking with his vet for confirmation that he needs the lysine supplement at all. However, I'm not aware of any drug interactions. There are lysine treats that he might like, I'm not sure what the powder tastes like.

Updated on September 23rd, 2025

My cat has a URI. Is lysine safe and effective for their treatment?

It is if there is a potential for viral involvement! It certainly won’t hurt at least. Most upper respiratory infections may need an oral antibiotics as well. You can try a 1/2 teaspoon of children’s Benadryl as well twice a day which may help. If he isn’t improving, lethargic, or loses his appetite, I would have your vet take a look at him. I hope this helps!

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What supplements help a cat with calicivirus boost its immune system?

You can give Charlie an L-lysine supplement - this is an amino acid that has been shown to help the immune system fight off respiratory infections more effectively. Enisyl and Viralys are both good brands, and can be purchased over the counter without a prescription - just follow the dosing instructions on the label based on your cat's weight.

Updated on September 23rd, 2025

Food & Nutrition

Should I give my cat L-Lysine for immune support or is it useless?

Historically, Lysine has been encouraged to be used among cats, especially those that tend to have upper respiratory flare ups due to underlying viral disease. Lysine was thought to be an immune-booster and thought to help prevent these flare ups from occurring or reduce the symptoms when they did. Majority of evidence that exists supporting this is anecdotal, with those in the scientific community more on the fence about its effectiveness. We know quite surely it isn’t causing any harm in most product formulations. Bottom line is that the majority of cats function and live long healthy lives with or without Lysine. Proper diet and exercise are all that should be needed to obtain the nutrients necessary to thrive.

Updated on September 23rd, 2025

Is it safe to give L-Lysine to a nursing kitten I bottle feed?

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! There is no research on giving L-lysine to nursing kittens. It seems safe to give to pregnant and lactating queens. It can cause an upset stomach. Since whether L-lysine is controversial whether it even helps for feline herpes I wouldn't risk giving it to such a young cat. I hope this helps!

Updated on September 23rd, 2025

Does lysine supplement really work for cats with herpes virus?

I would have to respectfully disagree with that statement. I have used Lysine for years and many cats have improved with it. The limitations are that it probably only works for Herpes infection (not other upper respiratory viruses in cats, and we don't often do testing to know for sure that it is Herpes virus causing the clinical signs), and it only works to slow down the replication of the virus (not eliminate the infection). I have attached 2 handouts below which discuss using Lysine in feline Herpes virus. (The first one discusses how Lysine works.) https://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=1327 https://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=613 I hope that answers your question and was helpful. Thanks for using PetCoach.

Updated on September 23rd, 2025

What to do for feral cats with goopy eyes, runny noses, sneezing?

You can try starting them on an L-lysine supplement - this is an amino acid that has been shown to help the immune system fight off respiratory infections more effectively. Enisyl and Viralys are both good brands, and can be purchased over the counter without a prescription - just follow the dosing instructions on the label based on your cat's weight.

Updated on September 23rd, 2025

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