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🐾 Keep your cat thriving with Viralys — the daily lysine boost they actually crave!
Vetoquinol Viralys is a 100g flavored oral powder supplement delivering 500mg of L-Lysine hydrochloride per serving, designed to support eye health, respiratory function, and immune strength in cats and kittens. Its palatable fish and chicken enzymatic flavors make daily administration easy, helping to reduce symptoms of feline herpes and upper respiratory infections while promoting overall wellness. Trusted by vets and loved by cats, Viralys offers a cost-effective, scientifically-backed solution to maintain your pet’s vitality.












































| ASIN | B000FULBT4 |
| Active Ingredients | Active ingredients: L-Lysine hydrochloride, 500mg. Inactive ingredients: Brewer’s Dried Yeast, Hydrolyzed Fish (enzymatic), Hydrolyzed Poultry Liver (enzymatic), Mixed Tocopherols (a preservative), Sodium Acid Pyrophosphate, Sodium Sulfate. Active Ingredients Active ingredients: L-Lysine hydrochloride, 500mg. Inactive ingredients: Brewer’s Dried Yeast, Hydrolyzed Fish (enzymatic), Hydrolyzed Poultry Liver (enzymatic), Mixed Tocopherols (a preservative), Sodium Acid Pyrophosphate, Sodium Sulfate. See more |
| Best Sellers Rank | #1,715 in Pet Supplies ( See Top 100 in Pet Supplies ) #4 in Cat Multivitamins |
| Brand | Vetoquinol |
| Brand Name | Vetoquinol |
| Customer Reviews | 4.6 out of 5 stars 9,613 Reviews |
| Flavor | Flavorless |
| Global Trade Identification Number | 00030521041480 |
| Included Components | Vetoquinol Viralys Powder, 100gm |
| Item Form | Powder |
| Item Weight | 0.27 g |
| Manufacturer | Vetoquinol |
| Manufacturer Part Number | 410633 |
| Model Number | 410633 |
| Number of Items | 1 |
| Product Benefits | Immune Support |
| Specific Uses For Product | Active |
| Target Species | Cat |
| UPC | 030521041480 884291149927 |
| Unit Count | 2.5 Ounce |
| Volume | 3.5 fluid ounces |
J**Y
GREAT FOR FELINE HERPES! LYSINE SUPRESSES THE AMINO ACID ARGININE, RESPONSIBLE FOR FLARE UPS!!!
I work w/ my local VSA ( voluntary services for animals). I took in a few kittens that's eyes were almost completely shut with crust & their little noses were covered in crust & mucus. A pitiful site :( . I quickly took all 4 to the vet within 24 hrs. WELL, after they said it was "Feline herpes", (an upper respiratory infection that doesn't go away but can be controlled) IT ended up costing me close to $800!! With Vet costs, testing costs, & the "Wonderfully expensive" medication they gave me for Each cat, That helped some but not much!! They had liquid meds, meds that had to be put INTO their eyes like 4xs a day, & some other antibiotics. It was awful , & seriously it didn't help much at all. It lessened it some, but they needed the meds constantly! I looked on the Internet for any info I could find & found out about LYSINE !! I really thought it was a bunch of "bull" but was willing to TRY anything! I 1st bought a paste & a gel- the cats hated it. I then bought this powder. I mixed it into wet food ( not too much or they taste it!) & they ate it! After a week I noticed all their symptoms were really improving! I had STOPPED the Vets meds as the cost was killing me & not really helping them. After a MONTH all the cats were totally better, no crusty gooey eyes, no crusty nose, sneezing, ALL GONE!! I was amazed!! I studied it more, the use of L LYSINE & it's effects. It surpresses what makes the Herpes virus flare up in the system, so taking it on a Dailey basis means you won't get the flare up & the full blown symptoms! It also works in humans as well. I kept the kittens & have given them forms of LYSINE for 2 yrs now & they have NOT had another flare up since! If I stopped it for a few months, I noticed some sneezing & gunk in their eyes in the 1st year & quickly put them back on it! With 5 cats ( I had a 3 yr old when I took these in, she caught feline herpes from them as well!) it's kinda hard to make sure each one gets 250 - 500 mg Ea. When they eat out of each others bowls! So I just put a scoop into 1 3 oz can of wet, feed them 3 cans & it works great. I tried the TREATS, most cats don't care for them, also many brands you have to give each cat like 10 treats 1-2 x a day! Woa! Or another brand the treats were huge! Only 2 a day because they were the size of a golf ball! Lol. So, the cat powdered LYSINE works good, it's flavored mixes well in food & good to start on. I had no luck putting this on DRY food, I have heard many ppl do that but my cats wouldn't eat the food & most just fell to bottom of dish/bowl. I also bought & use HUMAN grade LYSINE 500 mg tablets & crush them up w/ a spoon & mix into wet food. This is VERY cost effective! It taste stronger than this flavored powder, so use a good wet food to mix with & you wont have a problem. My cats got use to it fast. You can also buy LYSINE powder in BULK on here, it's human grade & already finely crushed up. It works GREAT & cost MUCH less. Plus I like that it's "human" grade. I now can skip months at a time with no LYSINE & they still get no flare ups. This LYSINE is a God send! I recommend this powder if starting out, it's flavored and cats will take it well. But cost wise, the pills, tablets, capsule at your store or on here ( cheaper!) are strongest & the best I've found( crush up finely) . bitter, but cats really don't "taste" bitter I've heard. Either WAY or BRAND you choose it will all but cure your cats of the virus, you won't have huge vet bills & expensive meds that are worthless. 5 cats taking LYSINE on & off for 2 yrs and they have NO MORE SYMPTOMS & are very happy healthy spoiled kitty's... So please do yourself, your wallet, & your cats a favor & put them on a LYSINE regimen of 250 mg a day OR - 500 mg 1-2 x's a day for a flare up or to start off with. Once symptoms subside, you can stay with 250 mg a day to keep them away for good! Btw, In order to replicate & cause FLARE UPS , in humans & cats the herpes virus needs "ARGININE" another amino acid such as LYSINE . when LISINE is taken at higher doses, it prevents the amino acid ARGININE from over producing & hence preventing outbreaks of the herpes virus. So just check your pets FOODS, TREATS etc for any ARGININE ( L-ARGININE ) in them as this will ADD to your problem!! There ARE foods with this in the ingredient list I've found, so just FYI to be safe. Hope this helps someone with the problems I went through & learned from along the way!! :) Jenn ~
M**O
tl;dr- powder dissolves easily and my fur babies love the flavor
After my one fur baby passed away, her sister was lonely so we decided to get another cat. Well that didn't go well as I was told that the cat had been socialized with humans and other cats... Well that was not true. The new cat was scared of my fur baby and well they both ended up getting stressed to the point that the herpes virus became an upper respiratory infection. -__- I didn't know that was a thing. Well both of them are now doing better and still getting used to each other. BUT they do like this supplement. The powder smells kinda fishy which is off putting for me BUT for them, they LOVE it. Lol I mix it into their wet food and they both gobble up their wet food. So apparently, it just taste good to them. They hated the paste that tastes like maple syrup... It was a struggle to get them to eat it. My fur baby hated the chicken liver flavored treats as well. This is the only one that she likes which is great as she has to eat it twice a day. Trying to force feed the supplement was a pain and added stress to my fur babies. The powder form mixed easily into their wet food and dissolves quickly which is great as my fur baby is a picky picky kitty and will stop eating if she doesn't like the food. -__- The ingredients look great and clean and this supplement is vet recommended which puts my mind at ease. Overall, this worked out the best for me and my fur babies as it made life so much easier for them and for me. Thank goodness!!
A**R
Boosts FIV kitty immune system
This is a very great supplement for FIV kitties. Used it for 1 year on my kitty before she passed at 16 years old. This definitely contributed to keeping her healthy.
L**H
A staple for pet lovers
I've had my car on this Lysine for years now and it truly keeps keep his feline herpes flare ups at bay. Even if he has a flare up this keeps them from getting out of control. I keep our other cat on it as well to protect her from his virus and she's free of it. I believe this really helps boost both their immune systems. Our vet originally told us about it and I was so happy to find it on here. Both our cats love the flavor and it smells just like fish - very important as cats depend heavily on their sense of smell for eating. It's super easy to mix in with their wet food and comes with a little scooper inside.
K**R
Works great for my cat's allergy issues, but watch for expiration date
Works great for my cat, 2x a day. Mix it in with his food, no problems. He has allergy issues and without this he'd be sneezing quite a bit. Started using this year for inside cat, but had previously used, off and on, for a feral with respiratory issues. Originally bought from vet and now with subscribe and save, definitely saving some $. One note, I received in September 2025, and just opened it, noticed expiration is 2/2026, which seems a fairly short time to use up. My 1st container I had a few years before expiring, and that was 1 I'd purchased from my vet. I wasn't sure if I'd have enough to get to my October subscribe and save delivery, so ordered in September. Will not place order until I absolutely need it, and definitely keep eye on expiration dates.
B**R
My picky cat LOVES this!
I’m not one to write reviews but this powder has been a literal godsend. I have a semi-feral 7 year old cat who’s had chronic sinus and eye infections her whole life. She will not take ANY medication and in fact goes on a hunger strike if I crush anything up to put in her food. I bought this hoping the flavor would entice her, and it is absolutely her favorite! She’s had no issues eating this mixed into her wet food and I’m noticing an amazing difference in just 4 days. She is sneezing WAY less than usual and her eye (which had started getting yucky again right before I bought this) has almost completely cleared up. Cannot recommend this enough!!
R**N
Vet recommended; looking for better adminastration
My best buddy "Bubba" a cat had past away and after a little while I was looking for another little four legged buddy; because I'm sure any of you out there who have a pet; it's one of Gods greats gifts. Anyway; I went to an Amish farm to see what I could find and there she was; a beautiful little kitten with a lot of issues. She had problems with her eyes and a lot of upper repertory problems as well. The kids on the farm caught her for me and I held her for a little while; before placing her in a pet carrier. I sat in my car for a while wondering if I should take this on due to what condition I seen she was in. I was going to let her go back into the barn but I knew in my heart that she may not make it with the condition she was in. Needless to say I feel in love with the little girl and took her to the vet to see what was going on with her and found out that she had FIV; which is an immune deficiency. Her one eye was pretty bad with ulcerations due to an upper repertory issue. She would sneeze a lot; as high as 10+ times in a row and would have a big discharge of junk. So she was treated for the upper repertory with amoxicillin and given eye drops. The after care was to use L-lysine. The gave us treats with the lysine in and she wouldn't eat them so we had to crush them and put them in her food. She could smell them in her food and then wouldn't eat her food either. We had to look for another way and find a more effective way as well. We would soak the treats in water and then mixing them in her food which in my mind was probably breaking down the Lysine. The treats worked but not as good as they should have. She don't even eat regular treats; she's just not a treats kitty. She don't do catnip either. We just received the shipment of this great product 3 days ago and she is showing signs of improvement already. Her eyes are not watering all the time and her sneezing has dropped to maybe once or twice a day and it's not loaded with all the junk; which she was hanging everywhere. Don't let the size of this container fool you as it did me. The dosage is 1 or 2 scoops a day. I didn't see the size of the scoop so I didn't know how fast the product would go down. How long it would last in plain words. The scoop is tiny; about the size of the bottom of a AAA battery. The diameter. As strange as it is most of the pet stores in my area don't carry this form of lysine so I decided to jump on amazon and give it a check and here it is. All in all a great product which I would recommend to anyone with a pet that sneezes a lot due to a condition like I have spoken about above. The severity of your animals health may not be the same as what I just described so I think it should work very well for any animal with a mild case of an immune system imbalance. Thanks amazon and the distributor of this product for making my little girl Jasmine Tangos life so much better! Spread the LOVE!
K**R
Actually noticeable effect in my cats well being after feeding in her wet food. A must buy!
My cat has feline herpes respiratory virus ( she was a stray I rescued and she’s hade it since she was a kitten) I have really struggled to do what I can to help her feel better, humidifier, eye ointment from the vet, comb her often since breathing is hard with a runny nose she’s not cleaning herself so I’ve gotten her combs but I bought this stuff and I noticed a definite improvement in her HIGHLY RECOMMEND! She seemed happier and more playful. It easily dissolves in the wet catfood ( I don’t recommend for dry but I think you can put in water - I personally wouldn’t recommend dry catfood for a cat with immune issues it’s just not good quality) But this is a good price the scoops last and any thing that helps the cat feels better is worth it for me, I’m going to try it in the paste form next and I’ll update on that! ( she seems to like the taste when it’s in her wet food) If you are not combing your kitty with respiratory issues I highly recommend that as well so the cat feels better. I noticed the older she gets that’s getting harder. And don’t forget to try a humidifier and I even use a gentle fan she seems to enjoy sitting in front of both… anything that helps!
B**I
Shelter cat approved
All my cats are from the shelter, and two of them are from the streets and they all suffer from eye issues, this stuff really helped us keep ontop of their eye health and they look and act so much happier with this powder in their wet food. we will be long time buyers of this product for sure
J**G
My cats like it!
I was recommended to buy this product as my cat had watery eyes and sneezes frequently. After taking this supplement, all is well. I give it to both cats and they liked it maybe because of the chicken and fish flavour.
J**A
Works well
This is very good tonic for cats
D**N
Herpès félin
Très bon , mon chat a arrêté de éternuer après 3 jours ( herpès félin )
D**E
La lysine renforce le système immunitaire
Excellent produit.
Trustpilot
1 month ago
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