Lysine Supplements

syzygycat

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They've been proven to do nothing to fight or prevent virus and possibly make it worse, but they are still an essential amino so; do Lysine supplements have any benefit?

I have 150+ lysine treats left, do I throw them away or feed them to my cats (occasionally)
 

Azazel

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They haven't necessarily been proven to not work for all cats. The research you're referring to is based on a meta-analytic study. Meta-analysis computes an overall effect size across different studies. The effect size is an "on average" estimate. Some studies have found that the medication does help, on average, while others have found that it doesn't. The meta-analysis showed that, on average, there doesn't seem to be an effect across all of the studies. This doesn't mean that it definitely won't work for your individual cat. Many people have observed positive outcomes from using lysine supplements, but the problem here is that it's based on individual observation and people's observations can often be biased or plain wrong.

So I guess what I'm trying to say is... if you used it for several months and saw no changes in your cat then it's probably not doing much, but if you haven't used it yet, give it a try for a few months and see what happens. It shouldn't hurt as long as you are staying within the recommended dosage.
 

BaileyCat

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I am believer that L-lysine pure powder (not the treats) works.
 

dkb817

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Simon had one heck of an URI when we first adopted him from the shelter - When nothing else was working, the vet recommended we try adding L-Lysine paste to his wet food, saying that some cats apparently just don't have the proper amount of the amino acid (they weren't sure why). With the exception of a couple of breakthrough colds, he hasn't had ANY major respiratory illness since adding the L-Lysine - but if I go a couple of days without, he begins to show signs of breakthrough illness.

My vet pretty much asked that I only use the paste so we knew for sure how much of the actual lysine was getting into his diet.

(Also completely off topic BaileyCat BaileyCat but the cat your avatar reminds me of the instagram famous cat, Bailey and their new cat, Carrot - So adorable! I miss my orange guy dearly)
 

Azazel

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but if I go a couple of days without, he begins to show signs of breakthrough illness.
That’s really strange since it’s an amino acid and not a drug. Its effects shouldn’t be showing or wearing off in a number of days.
 

lisamarie12

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When that 2015 study first came out re: lysine being ineffective for FHV cats, I asked our vet and he kind of rolled his eyes and said to continue using lysine (during flare ups for our FHV male cat). I use it intermittently, the only issue is not to overdue with lysine because it reduces arginine (another essential amino acid for cats).

I try to concentrate on improving Mikey's overall immune system, for the past several months I've been using Vetri's DMG liquid, added to his food. This seems to be helping him, he rarely has flare-ups.

I don't give lysine to our other cat who doesn't have FHV.
 

lisamarie12

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I am believer that L-lysine pure powder (not the treats) works.
I've used both pure powder (Carlson's) and lysine treats and found both to be effective, it may just depend on the cat although likely the powder is more concentrated. When I used the powder, my cat wouldn't eat all his food with the powder mixed in but would eat the treat.
 
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syzygycat

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They haven't necessarily been proven to not work for all cats. The research you're referring to is based on a meta-analytic study. Meta-analysis computes an overall effect size across different studies. The effect size is an "on average" estimate. Some studies have found that the medication does help, on average, while others have found that it doesn't. The meta-analysis showed that, on average, there doesn't seem to be an effect across all of the studies. This doesn't mean that it definitely won't work for your individual cat. Many people have observed positive outcomes from using lysine supplements, but the problem here is that it's based on individual observation and people's observations can often be biased or plain wrong.

So I guess what I'm trying to say is... if you used it for several months and saw no changes in your cat then it's probably not doing much, but if you haven't used it yet, give it a try for a few months and see what happens. It shouldn't hurt as long as you are staying within the recommended dosage.

Virus' spread by causing an infected cell to very rapidly replicate the viral DNA. One of Lysine's roles is to regulate DNA replication, so the belief for decades was extra Lysine would deter viral DNA replication rates.
The 2015 Feline herpes is one example, there are hundreds of human studies that show virus' need Lysine to replicate the same way healthy DNA does, Lysine won't do anything so prevent or slow viral DNA transcription.


Cats (like humans) need more nutrients when fighting off an illness but usually eat less. A sick cats risk for a cat to get a nutrient deficiency is higher. Maybe that accounts for the circumstantial evidence that Lysine is helps some sick cats during FHV or URI flare ups.

I'm no expert but supposedly 7-10lb cat eating mid grade cat food is getting 1000mg-2800mg lysine. The math makes sense that a 500mg lysine supplement helps cats who eat less when they're sick.

My cat's are on the chubby side, even if they eat less when they're sick, theyre probably still getting more than enough lysine.

I love my vet, but her veterinary knowledge is 15+ years out of date, meanwhile research scientists over dramatize new findings* and the internet sensationalizes them.

Lysine won't cure anything, but supplemental lysine might have some benefit to a healthy cat, if it does, that knowledge is buried onlinr by the former. Which is the original question, do we know if lysine supplements do anything non-illness related, Or is s it just a waste of time and money.
 

sivyaleah

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Personally Lysine made zero impact on my cats health. I used it regularly for several months when I learned my kitten most likely had been exposed to the herpes virus. And was worried about her spreading the virus to our older cat. It didn't help her when she had her kitten colds. It didn't help our older cat from getting that cold passed on to her. It didn't make those colds leave faster (the antibiotics did) and it didn't prevent reoccurence of infections All it did was take money from my wallet. My personal feeling after researching and speaking to my vet is it's more a placebo effect - people think it works because whatever illness the cat had goes through it's natural life cycle and leaves and the person thinks it's because of the lysine. Most likely - not.

Your mileage may vary, as they say.
 

molly92

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Virus' spread by causing an infected cell to very rapidly replicate the viral DNA. One of Lysine's roles is to regulate DNA replication, so the belief for decades was extra Lysine would deter viral DNA replication rates.
The 2015 Feline herpes is one example, there are hundreds of human studies that show virus' need Lysine to replicate the same way healthy DNA does, Lysine won't do anything so prevent or slow viral DNA transcription.
This is not the mechanism. Lysine is an amino acid with a long, positively charged residue. Arginine is an amino acid with a slightly longer, positively charged residue. The herpes virus is made of a lot of arginine, so inside a host cell, it needs arginine available to replicate. Without enough arginine, the virus won't grow.

Cats cannot make many amino acids on their own (and neither can humans, though we can make a few more than cats, hence the omnivore/carnivore distinction), so they get their lysine and arginine from food. Specific transporters pass these amino acids from the digestive system to cells that need them, but since arginine is so similar to lysine, lysine can go through the arginine transporters. The theory is, if you flood the system with lysine, lysine gets in the way of arginine getting passed into cells, and without enough arginine around, the herpes virus doesn't replicate.

The catch is, cats also need arginine for their own proteins. So is there a level of lysine dosage that reduces arginine availability enough to inhibit the virus, but not so much that the cat's own cells don't suffer? That's the big question. I don't know that we have a satisfying answer to that.

It might be something like zinc for a cold: yes it has been proven to help, but only at a formulation with a higher dosage than is commercially available. Or maybe it doesn't work at all without doing more harm than good. Or maybe it depends on the cat and some minor genetic differences in amino acid transporters.

Side note: it's very easy to establish through feeding trials which amino acids need to come from diet for cats, so these are all included at standard levels in commercial cat food today. It is unlikely that a cat on a commercial diet is deficient in any amino acid.
 

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MissClouseau

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I like multi-benefit supplements over singular-ingredient ones. They are my first to-go. There are multivitamins that contain lysine. I use one for street cats (and occasionally give to my Hima as well.) If the lysine in that works, great. If it doesn't work, they still get the other vitamins.

I have 150+ lysine treats left, do I throw them away or feed them to my cats (occasionally)
If they accept, you can also donate some to a shelter or alike
 

Oysterbay

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Lysine is dose-dependent - my holistic vet says it acts like a fire extinguisher so the more virus your kitty has, the more lysine she'll need. I have an FHV kitty whose immunity is quite compromised. After years of using lysine, a major flare sent me looking for something stronger. I find GSE (citricidal) to be easier and more powerful. It took care of things right away.
 

sivyaleah

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I'll just leave this here. Please before ever giving your cat any supplement/medication/etc to do your due research.

The mentioned supplement has no proof of it working and, more so, even if it did you don't what a proper dosage would be. You can't just randomly give any kind of medication or supplement to an animal without being able to calculate the right amount which will be of use.

Plus it's not manufactured per FDA regulations. Who knows if it's safe?

From Wikipedia:

Health claims and safety concerns[edit]
Although various health claims for using GSE are marketed in the dietary supplement industry, there is no scientific evidence from high-quality clinical research that it has any health effects, as of 2018.[3][4] Phytochemicals in grapefruit seeds, particularly furanocoumarins and flavonoids, may cause adverse effects on health resulting from grapefruit–drug interactions that influence the intended therapeutic effects of some 85 prescription drugs.[3][19] The main safety concern about GSE is inhibition of the liver enzyme, cytochrome P450, which controls liver metabolism of drugs; consequently its inhibition by GSE unpredictably increases the blood concentrations of prescribed drugs.[19]

FYI, same with Lysine and this has been known for years.

"Recent research is contesting that L-lysine may not be beneficial for treating cats with feline herpes virus like previously believed.

An industry leader, The Merck Veterinary Manual stated, “Previously lifelong oral L-lysine (250/500 mg per day) was recommended to help prevent or reduce the severity of feline herpes virus infections. However, recent work has shown that oral L-lysine can exacerbate the feline herpes virus.”

In 2009, an article published in the American Journal of Veterinary Research examined 261 cats, and determined that dietary lysine supplementation bore no influence on controlling or preventing infectious upper respiratory disease among cats. This study went on to demonstrate that L-lysine was an ineffective management tool for treating symptoms or flare-ups of FHV-1, and may even make the infection worse.

Then in 2015, the BMC Veterinary Research Journal published a study contesting L-lysine for cats is ineffective."
 

Oysterbay

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You'll find dosage recommendations on holistic vet Jean Hofve's site Little Big Cat. For an active flare, here's her suggestion:
"The dose of lysine for a cat with an active herpes flare up is a thousand milligrams a day one full gram. It’s very, very safe and it’s pretty darn effective."

I also love Dr Hofve's book The Complete Guide to Holistic Cat Care. It led me on my journey to curing pemphigus which is a deadly auto-immune condition, in my cat. As for manufacturers, NOW Foods is a reputable company that has been producing lysine supplements since 1968. This means it's been used for over fifty years and you'll find tens of thousands of satisfied users just scrolling through a search on Amazon!

For more on the safety and anti-microbial mechanism of citridal, here are the mechanism of action, suggested usage, toxicity, and anti-microbial performance as compared to over fifty other antimicrobials: https://www.naturalingredient.org/files/Citricidal Brochure.pdf. You can find a detailed review of their manufacturing process from their general manager Richard Perry here as well: The Natural Ingredient Resource Center because natural matters!.

Good luck and God bless! Much love from me and my twelve-year old kitty Chairman Meow.
 
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